At least nine people are reported killed in a suicide attack in the Iraqi city of Haditha.

Thirteen people were also injured in the bomb blast at a branch of the state-owned Rafidain bank on Thursday, medical and security sources told the Reuters news agency.

The bombing happened as people were queueing to collect their salaries, said police officer Ali al-Ubaidi.

"There was a group of Iraqi army soldiers standing in front of the bank to collect their salaries when a suicide bomber wearing a vest came in between them and blew himself up," he said. 

At least six of the dead were soldiers, Reuters reported.

Waleed al-Hadithi, manager of the general hospital in Haditha, said he expected the death toll to rise. 

Haditha is 190km northwest of Baghdad, the Iraqi capital.