By Andrew Osborn
MOSCOW (Reuters) - Two masked men set fire to the office of one of Russia's biggest human rights groups in southern Russia on Wednesday, an arson attack which the group, Memorial, said was part of a campaign to drive it from the region.
CCTV of the incident showed the men setting a ladder against the red brick building in Nazran, a town in the Russian region of Ingushetia which borders Chechnya, in the early hours of the morning and sparks leaping from its windows shortly afterwards.
Pictures of the office after the fire showed its blackened interior strewn with fire-damaged debris. Memorial said documents and office equipment had been destroyed.
Memorial is under pressure in the Muslim-majority North Caucasus region after police in Chechnya detained the head of its office there this month and accused him of possessing a large quantity of cannabis, a crime punishable by up to 10 years in jail.
Concerns about the case of the detained activist, Oyub Titiev, who has written to President Vladimir Putin saying he was framed and that the police planted the drugs in his car, prompted the United States and Europe to call for his release.
Memorial has angered authorities in Chechnya by reporting disappearances, torture and punitive house burnings there, and Titiev's predecessor, Natalia Estemirova, was kidnapped and shot dead in 2009. Nobody has been convicted of her killing.
Ramzan Kadyrov, the head of Chechnya, has said allegations that Chechen authorities use illegal violence are false and invented to secure foreign grants.
Memorial on Wednesday called on the authorities in Ingushetia to investigate the arson attack as an act of terrorism.
"The work of Memorial's representative office in Ingushetia is exclusively dedicated to human rights problems on the territory of Ingushetia and in no way linked to Chechnya," Memorial said in a statement.
"Nonetheless, it's obvious to us that there is a link between the arson attack with those forces who are trying to destroy the work of Memorial in Chechnya and squeeze Memorial out of the entire North Caucasus region."
Memorial staff handling the detention case had been based in Ingushetia and said police had frequently stopped them for document checks.
The Kremlin played down Memorial's problems. Spokesman Dmitry Peskov told reporters it would be wrong to draw any generalized conclusions about the detention of the Memorial activist, saying that only investigators were in a position to judge the nature of the allegations against him.
Peskov also cautioned against making a link between the detention and the arson attack, saying the incidents had occurred in two different regions.
(Editing by Hugh Lawson and William Maclean)