ATHENS (Reuters) - An explosive device went off close to a bank in a shopping centre near Athens on Sunday, lightly injuring two security staff and damaging stores, police said.

The explosion followed a spate of gun and makeshift bomb attacks on organizations, journalists and political figures in recent weeks, some claimed by groups angry about Greece's deep financial crisis.

The device, which exploded shortly before 11 a.m. (0900 GMT), was left in a rubbish bin close to a branch of National Bank at a large mall in the suburb of Maroussi, said police.

Security staff had already evacuated the mall after police told them about two warnings calls to a newspaper, made about half an hour earlier.

Police said they were combing the mall for other explosive devices and checking security cameras. They had received no claims of responsibility so far.

Greece is in the sixth year of a recession that has fuelled anger against banks, foreign lenders and the political class, blamed by Greeks for bringing the country close to bankruptcy.

Unidentified attackers opened fire on the Athens headquarters of Greece's governing New Democracy party with a Kalashnikov assault rifle on Monday, in what the government said was a worrying escalation in political violence.

(Reporting by George Georgiopoulos; Editing by Andrew Heavens)