ATHENS (Reuters) - A bomb exploded on Tuesday outside the Athens offices of JP Morgan, the second largest U.S. bank by assets, causing minor damage and no injuries, police and the company said.

Police cordon off a street after a bomb went off in the Kolonaki district in central Athens February 16, 2010. REUTERS/John Kolesidis

The explosion is the latest in a series of blasts that have rocked the country since the police killing of a teenager in December 2008 sparked the country’s worst riots in decades.

“It was a time-bomb outside JP Morgan’s offices at the second floor of an Athens building,” said a police official who declined to be named.

“The explosion damaged the door, furniture, computers and smashed some windows,” the official added.

Police had cordoned off the area after a local newspaper received a warning call. Ambulances and fire engines blocked streets in the upmarket central district of Kolonaki, where JP Morgan’s Greek offices are situated, a Reuters witness said.

JP Morgan confirmed the incident and said there were no injuries.

“No one was hurt,” said a JP Morgan spokesman in New York. “The company is still gathering details about the situation.”

In 2007, the New-York based firm came under scrutiny by Greek investigators’ after underwriting 280 million euros ($382.2 million) of structured government bonds which ended up with state pension funds at inflated prices.

JP Morgan, which denied any wrongdoing, agreed to buy back the bonds and reverse the deal.

Banks, foreign companies and police are a frequent target of leftist groups in Greece. No group has yet claimed responsibility for the attack, the official said.

Urban guerrillas exploded a makeshift bomb outside Greece’s parliament in January, causing no injuries and minor damage.

In other attacks since the teenager shooting, guerrilla groups killed a Greek antiterrorism officer and bombed the Athens Stock Exchange.