TEHRAN (Reuters) -- Two small bombs exploded in the northwestern Iranian city of Kermanshah on Monday, wounding at least seven people, an official was quoted as saying.

"The two blasts injured seven people at the governor's office and the trade organization’s building on Monday," the official IRNA news agency quoted Babak Izadi, head of Kermanshah's medical faculty, as saying.

Kermanshah's governor Hossein Khosheghbal told state television the blasts caused minor damage to government buildings and smashed some windows.

"Police and security forces are investigating the bombings," Khosheghbal said.

No group claimed responsibility for the attack.

The first bomb went off at around 1:50 pm and the second one exploded minutes later in another government office for commercial affairs.