(Updates with Tikrit dateline, quotes from witness)
TIKRIT, Iraq, July 28 (Reuters) - Two suicide bombers killed at least 15 people and wounded more than 30 in Iraq's Tikrit city as police and soldiers were collecting their salaries at a local bank, police and hospital officials said on Thursday.
The attacks were the latest to target local Iraqi security forces as the last U.S. troops prepare to pull out of the country more than eight years after the invasion that toppled Saddam Hussein.
One suicide bomber detonated his explosives among officers who were gathered outside the Rafidain bank in the centre of Tikrit, 150 km (95 miles) north of Baghdad, and moments later another blew up a car when emergency workers arrived, police said.
"Just a few minutes after I entered I heard a huge explosion, we ran outside to see what was happening, I saw bodies and the wounded all over the place," said Assam Dhiyab, a policeman who was collecting his unit's wages in the bank.
A Tikrit hospital official said at least 15 people were killed and more than 30 wounded in the blasts. Most of the casualties were Iraqi soldiers.
Television video showed a column of black smoke rising from the blast site.
"Initial indications are that the first explosion was a suicide bomber wearing an explosive vest with a large amount of explosive," said police lieutenant Mohammed Naif, an explosives expert in Tikrit.
"According to witnesses the bomber was targeting a group of soldiers and officers of the Iraqi army."
Tikrit, Saddam's hometown, is dominated by Sunni Muslims and suspected Sunni Islamists tied to al Qaeda have carried out frequent attacks in the town this year.
Tikrit was the site of two of the deadliest attacks in Iraq this year. On Jan. 18 a suicide bomber attacked a police recruiting centre, killing 60 and wounding more than 100.
On March 29 militants took hostages at the provincial council headquarters and fought security forces. At least 53 people were killed and scores wounded.
On June 3, two blasts in the city, one targeting worshippers in a mosque, killed 21 and wounded 70. Three days later a suicide bomber detonated a car at the entrance to a complex of palaces once used by Saddam, killing 13 people.
Violence in Iraq has dropped sharply from the height of sectarian killing in 2006-2007, but insurgents and militias still carry out daily attacks and assassinations in an attempt to undermine the government.
Local police and soldiers have been increasingly targeted both by Sunni and Shi'ite armed groups. Insurgents often set off one blast and then detonate another when emergency forces arrive to evacuate the wounded.
The remaining 46,000 American troops in Iraq are due to leave by the end of this year. Iraqi forces say they can contain internal threats but acknowledge they need more training to plug capability gaps. (Reporting by Muhanad Mohammed in Baghdad, Ghazwan Hassan in Tikrit; Writing by Patrick Markey; Editing by Karolina Tagaris)