Greek militant group claims Microsoft attack

A security guard stands outside Microsoft's Greek headquarters following an attack at Marousi suburb, north of Athens June 27, 2012.

ATHENS (Reuters) - A little-known leftist militant group claimed responsibility on Friday for an attack on Microsoft's (MSFT.O) Greek headquarters earlier this week.

Hooded attackers rammed a van packed with gas canisters into the Microsoft building in Athens on Wednesday and then set the vehicle on fire, causing damage but no injuries.

At least two people wielding pistols and a machinegun kept security guards away as they carried out the attack, police said.

In a statement published on the Internet, the International Revolutionary Front said it singled out Microsoft to strike a blow at capitalism.

"We chose this building because Microsoft is one of the most powerful companies of the computer sector ... which is now carrying capitalism on its shoulders," it said.

The group said it also carried out the attack as a sign of support to other militants currently detained by police in Greece and Italy.

The statement made mention of Ted Kaczynski, also known as the "Unabomber", who conducted a mail bomb campaign in the United States over almost 20 years.

Arson attacks against domestic and foreign banks and local politicians have become more frequent in Greece in recent years as the country battles soaring unemployment and struggles through a recession deepened by austerity policies imposed by foreign lenders.

The International Revolutionary Front made its first appearance last year, carrying out arson attacks on the private vehicles of policemen as well as on a branch of U.S. fast-food chain McDonald's.

"We are taking the claim seriously and are investigating its authenticity," a police official told Reuters on condition of anonymity.

(Reporting by Harry Papachristou and Renee Maltezou; Editing by Ralph Gowling)