BERLIN (Reuters) - A French terrorism alert about Britain and attacks on Europeans in Yemen added to Western security concerns on Wednesday, but Germany sought to calm nerves, saying too much public talk of risks would stir fear.
Suspected al Qaeda militants attacked two Western targets in Yemen, firing a rocket at a senior British diplomat's car and killing a Frenchman at a gas and oil installation.
France became the latest country to issue a security alert, telling citizens heading to Britain to use caution due to a very high risk of terrorist action. An official said the alert merely reflected Britain's own risk assessment.
That followed a U.S. advisory on Sunday warning American citizens to exercise caution if traveling in Europe. The same day, Britain raised the threat level to "high" from "general" for its citizens traveling to Germany and France.
But in Berlin, Interior Minister Thomas de Maiziere said he saw no signs of any imminent attack on Germany, even though the country was in general a target. Talking about possible attacks played into terrorists' hands by fuelling public fears, he said.
"Public discussion is something terrorists use because they want to spread fear. We're working but not talking a lot," de Maiziere told Deutschlandfunk radio.
Security sources say the trigger for the series of warnings was intelligence about a possible al Qaeda-related plot to launch assaults on European cities, modeled on the 2008 Mumbai attacks by Pakistan-based gunmen that killed about 170 people.
In Budapest, visiting U.S. Deputy Secretary of State Jim Steinberg said Washington was simply trying to urge vigilance.
"We are not trying to discourage people from going about their normal business," he said. There was a threat, but Washington had been very measured in what it was trying to say.
In Islamabad, Pakistani security officials said they had seen no information about the alleged European plots beyond what was reported in the media.
The media attention on the threat of terrorism originating in Pakistan is adding to tension between Islamabad and Western governments and seen as adding to pressure on Pakistan to "do more" to tackle militants.
"Already we are doing the heavy lifting beyond our capacity. Any expectation more than that would be unjustified," said one Pakistani official."
De Maiziere called the danger to Germany "hypothetical."
He said he could not confirm accounts from Pakistan that eight militants of German nationality had been killed by a suspected U.S. missile strike in northwest Pakistan on Monday.
In Yemen, a Frenchman was killed in a shooting incident inside the compound of Austrian-owned oil and gas group OMV, France's Foreign Ministry said.
Britain's Foreign Office said a missile was fired at an embassy vehicle carrying the deputy head of the British mission in Sanaa, the Yemeni capital. One staff member suffered minor injuries.
A range of security challenges in Yemen including al Qaeda attacks have raised concerns it could become a militants' haven.
Sunday's vague U.S. alert about attack risks in Europe was evidence of Washington's heightened sensitivity to possible attacks after more than a year of failed but brazen strikes on domestic U.S. targets by homegrown militants, often Americans.
French authorities issued an advisory about Britain late on Tuesday urging travelers to be extremely vigilant on public transport and at popular tourist sites.
Foreign Ministry spokesman Bernard Valero said: "We don't want to be too alarmist, but want to keep a high level of preparedness on this issue."
Britain's threat level at home was raised to "severe" on January 22 this year. "The French saying an attack is highly likely is true because that is where our threat level is," said a spokeswoman for London's Counter Terrorism Command.
In Bulgaria, police raided offices and homes belonging to an unregistered branch of Islamic foundation Al Waqf-Al Islami in a joint operation with prosecutors and the state agency for national security, the interior ministry said.
Police found propaganda materials inciting religious hatred and seized documents proving the branch was funded illegally.
Al Waqf-Al Islami was set up in the Netherlands and funded mainly by "Salafi circles" from Saudi Arabia, the ministry said, referring to an ultra-conservative brand of Islam.
Speaking in Brussels, EU Counter-Terrorism Coordinator Gilles de Kerchove suggested one possible reason al Qaeda was seeking to mount something "symbolic" was to repair its prestige amid heavy pressure from drone strikes in Pakistan.
Additional reporting by Paul Carrel in Berlin and Vicky Buffery in Paris, Michael Holden in London, Irina Ivanova in Sofia, Justyna Pawlack in Brussels, Krisztina Than in Budapest; Editing by William Maclean and Charles Dick