* Oil workers state new protests in western region
* 15 killed in earlier clashes
* Nazarbayev presses on with visit to Moscow
* Zhanaozen bloodshed an end to "beautiful epoch" - analyst (Adds analyst)
By Robin Paxton
AKTAU, Kazakhstan, Dec 19 (Reuters) - Hundreds of oil workers held a third day of protests in the capital of Kazakhstan's western oil-producing region on Monday, after at least 15 people were killed in the Central Asian state's deadliest riots in decades.
About 400 protesters confronted lines of police, some of whom were armed with automatic rifles, in the main square of Aktau, the capital of the Mangistau region where the clashes broke out.
"We are not looters!" read one of the protesters' banners in response to an accusation by the former Soviet republic's authorities.
Kazakh President Nursultan Nazarbayev, who has run the vast oil-producing nation of 16.6 million people since Soviet days, has declared a state of emergency in Zhanaozen, a Mangistau oil town where the firing of oil workers sparked clashes on Friday.
Officials said 14 people were killed in Friday's clashes with police in Zhanaozen. One person was killed in the village of Shetpe in the same region on Saturday and a total of about 100 people were wounded in the violence.
The authorities blamed the clashes in Zhanaozen on "hooligans and looters and oilmen who joined them", saying they torched dozens of official and private buildings and cars, and plundered bank cash-machines. Security forces are out in force.
"One of the main demands is to withdraw troops from Zhanaozen," Kenzhegali Suyeov, the head of the region's independent trade union, said.
Zhanna Oishibayeva, adviser to the Mangistau governor, said the protesting oil workers had met senior Aktau officials on Monday, demanding an increase in their wages.
"They also asked city authorities why civilians had been shot in Zhanaozen," she told Reuters. "The rally is being held peacefully, there are no clashes."
The latest outbreaks of violence and rallies are unprecedented in modern Kazakhstan, where Nazarbayev enjoys sweeping powers and brooks no dissent.
The 71-year-old former steelworker has overseen rapid market reforms and massive foreign investment, but has put democratic reforms on hold, saying that he treasures "stability and harmony" in his multi-ethnic country.
"What happened is an end to the 'beautiful epoch', as Nursultan Nazarbayev's reign had been presented to the world before," Arkady Dubnov, a Moscow-based Central Asia pundit, told Reuters.
"The myth of a stable Kazakhstan thriving under his wise leadership has vanished. Kazakhstan still remains an economically successful country, but one can no longer say that this country is stable politically."
The suppression of the riots has featured a lot on social networking sites in Kazakhstan. Protesters have picketed Kazakhstan's embassies in Moscow and London, and a rare opposition protest has been held in Kazakhstan's commercial capital and biggest city, Almaty.
About 12 demonstrators were detained by police on Monday as they tried to deliver an open letter in support of Zhanaozen workers to Nazarbayev's palace in the capital Astana.
"Don't shoot people" and "Blood is cheaper than oil", read their posters.
Nazarbayev has promised to hold a transparent investigation into the Zhanaozen bloodshed.
But as Nazarbayev arrived in Moscow on a two-day visit on Monday, Foreign Minister Yerzhan Kazykhanov maintained the official line, saying "bandits" had sparked the riots.
"An oilmen's work dispute should by no means be confused with illegal acts by criminal elements trying to use it in their criminal interests," Russian news agencies quoted Kazykhanov as telling reporters on the sidelines of the visit. (Additional reporting by Raushan Nurshayeva in Astana and Mariya Gordeyeva in Almaty; Writing by Dmitry Solovyov; Editing by Peter Graff)