Bombs killed six people and wounded several others in the south-western city of Ahvaz on Tuesday, Iranian state television reported.
Fire engines and ambulances rushed to the site of the explosions, a state environmental agency building and a bank in Ahvaz, the capital of oil-rich Khuzestan province, the official Islamic Republic News Agency said.
The blasts damaged the buildings, the television reported.
Ahvaz witnessed explosions in June and October last year that the government blamed on Iranian Arab extremists whom it claimed had ties to foreign governments, such as Britain.
The October bombings killed six people and those in June killed at least eight people.
In recent weeks, Iran has repeatedly accused Britain of provoking unrest in the Khuzestan province, which borders that part of Iraq where 8 500 British soldiers are based as part of the United States-led military coalition.
Britain has denied it has any connection to unrest in Khuzestan. — Sapa-AP