MOSCOW Russian stock markets and the ruble weakened on Monday after news that at least 31 people were killed and more than 100 injured in a suicide bomb blast at Russia's biggest airport Domodedovo.
Below is a selection of comments about the attack:
CHRIS YATES, BRITISH AVIATION SECURITY CONSULTANT
"If this happened at the international baggage reclaim, that suggests this device was taken in by someone working within the airport or with a security badge."
"If this was in domestic baggage reclaim, then it could be different. At an awful lot of airports, there's no great checks at domestic reclaim. You just take your bag off the carousel and wander out. People can just walk in off the street.
SAMANTHA WOLREICH, SENIOR RISK CONSULTANT, AKE LTD
"The suspected suicide blast ... raises significant concerns about the internal security measures currently in place at all Russian transport hubs. This topic is particularly timely following the official designation of Russia as the host nation for the 2018 FIFA World Cup, and calls in to question the Russian government's ability to safeguard its own citizens, as well as international visitors."
"This appears to be a well co-ordinated and planned attack, indicating it was carried out by a group with significant funding, potentially coming from outside Russia. The identity of the bomber(s) is yet to be confirmed, but this could corroborate links between Caucasus-based insurgents and international terror groups which have as yet remained somewhat unsubstantiated.
"In the short-term security measures at all transport hubs will be visibly stepped up, whilst President Medvedev and Prime Minister Putin will seek to reassure the nation and international observers with hard-line and frank rhetoric vowing retribution against those responsible. This could take the form of reinvigorated military or FSB action in the North Caucasus, which in the mid- to long term will exacerbate existing inter-ethnic tensions. Security for all international events, such as Sochi 2014 and the Asian Winter Games in Kazakhstan later this month will also be subject to greater scrutiny."
BRIAN GLYN WILLIAMS, ASSOCIATE PROFESSOR OF ISLAMIC HISTORY,
UNIVERSITY OF MASSACHUSETTS AT DARTMOUTH.
"This has all the hallmarks of north Caucasus-based terrorism. Dagestan is increasingly the epicenter of violence in the north Caucasus.
"This will certainly exacerbate tensions between ethnic Russians and peoples of Caucasian descent living in Moscow and other locales in Russia."
"Russian ultra-nationalist groups may well scapegoat people with Caucasian backgrounds.
"As for Russian security measures there is not much they can do ... They are already waging a proxy war in Chechnya and using local police forces to fight terrorism in Dagestan, Kabardino-Balkaria, Ingushetia etc.
"I believe this bombing is an effort to remind the Russian people and the world that the war in the Caucasus is far from over."
TEYMUR HUSEYNOV, HEAD OF EURASIA DESK, EXCLUSIVE ANALYSIS
"There is lax security at the arrivals gate so you can easily park your car or take a train to the airport and enter. There is no limitation on the entry of people who are meeting those arriving."
"They are approaching the election period in Russia -- in December 2011 parliamentary elections and in March 2012 presidential elections -- so different insurgent groups, many of whom are not necessarily coordinated with each other apart from the loosely coordinated Caucasus emirate, are likely to attempt to undertake such attacks in order to damage the image of the state and especially the image and reputation of the prime minister and the security services."
"The confrontation between the slavic and ethnic Caucasian communities is exactly the kind of event this kind of terrorist action can lead to.
If we continue on this trend we are definitely likely to see more attempts by these groups to strike key Moscow assets. It's difficult to do it (stage attacks) in central Moscow, apart from soft transport assets, but it's easier to do it against the airport."
JUSTIN CRUMP, CEO, SIBYLLINE SECURITY CONSULTANCY
"This was almost certainly the Islamic Emirate of the Caucasus. We've seen before how terrorists have attacked Russian aviation by bribing their way on board, something that's very possible on internal flights in Russia"
GLEN HOWARD, PRESIDENT OF U.S. JAMESTOWN FOUNDATION RESEARCH
"The recent riots in December by Russian nationalists at Manezkha Square have created a dangerous environment in Moscow whereby Putin is seen backing the nationalists, while the peoples of the North Caucasus feel that Moscow is taking sides by backing the nationalists."
"The attacks in Moscow are going to further exacerbate the tensions created by the right wing demonstrations in Moscow and may result in further pogroms against people from the North Caucasus.
"It does not forebode well for Russian ties to the North Caucasus and is yet another sign that what Putin started in 1999 by invading the rebellious republic of Chechnya has come home to roost again in the Russian capital.
"The bomb blast at Domodedovo will further strengthen the view among the Russian elite that Putin is losing control over security in the capital, which plays into the hands of his enemies, who I am sure you can now count as (dismissed Moscow mayor Yuri) Luzhkov and others."
PAUL ROGERS, PROFESSOR OF PEACE STUDIES, UNIVERSITY OF
"As to the likely suspects, one would have to say Caucasus, mostly likely Chechen-connected. There is a secondary possibility of a criminal network, ie some sort of extortion. That's a possibility, but lower down the list."
MATTHEW CLEMENTS, IHS JANE'S EURASIA ANALYST
"From initial reports it seems to have been a suicide bomber. Based on that, I would say the attack is almost certainly going to be associated with militants operating from the North Caucasus. This would be in line with their tactics and strategy, and civilians at airports would be a prime target in that strategy."
ALEXEY SUROV, TRADER, BANK ZENIT
"Based on previous experience with the Russian market falling after terrorists attacks, I don't think the market will stay down on the news for more than several days.
Aeroflot shares are down because investors are afraid the company's revenue will go down, as strengthened security measures will lead to fewer flights and fewer people flying to and out of Moscow."
JOHN WINSELL DAVIES, LEAD FUND PARTNER, WERMUTH ASSET
"The Russian RTS (index) traded higher just five days after the Nord Ost hostage crisis. The RTS straight-line rallied 7.5 percent in the month of September following the Beslan school tragedy. Moscow does not believe in tears."
ZSOLT PAPP, UBP ASSET MANAGEMENT, ZURICH
"I don't think any major investor will be deterred by a bomb attack from investing in any major Russian company. Russia is politically a stable country, remarkably stable, and other factors such as the oil price, play a much bigger role. For the kind of privatization that the government is lining up -- medium to long-term players -- I don't think this will have an impact."
YEVGENY GONTMAKHER, INSTITUTE OF MODERN DEVELOPMENT
"This tragic event will in no way influence Russia's business climate, which is (already) unfavorable. The business climate is determined by more stable circumstances such as corruption and state interference with business, not by one-off events like this"
ALEXEI BACHYURIN, TRADER, RENAISSANCE CAPITAL
"It (the blast) is moving the market in the short term, but there is no fundamental reason for the market to fall. If you remember, the market didn't react strongly to (previous blasts).
YAROSLAV LISSOVOLIK, CHIEF STRATEGIST, DEUTSCHE BANK
"I don't think there will be a long term effect... We are already seeing some negative impact (on markets), but in the long run there will increased safety measures on flights and in airports. Gradually this negative impact will disappear, as we saw in past episodes of such events."
VLADIMIR BRAGIN, ANALYST, ALFA BANK
"The blast, and the measures the government undertakes, will affect everything: first the transport industry, then infrastructure as a whole, which will in turn affect the oil sector. Additional security measures that may be introduced will probably scare some investors."
ILYA MAKAROV, ANALYST, ATON
"The market reaction was negative. We had fallen by 1.3 percent (before the blast), and now by around 2.2 percent. The market was down because of Sberbank and Aeroflot, which are both state companies and always react first on such news. There are a lot of emotions."
(Reporting by Moscow Newsroom)