Baghdad - A suicide bomber killed at least 15 people mourning at a Shi'a funeral in the northern Iraqi city of Baquba on Monday in the latest sectarian attack this month.

A wave of bombings on Shi'a pilgrims and religious sites has killed more than 130 people in June, reviving fears of a return to widespread sectarian violence, in some of the bloodiest attacks since US troops left Iraq in December.

The bomber on Monday blew himself up inside funeral tents where mourners in Baquba were paying respects to the family of an influential Shi'a tribal sheikh, witnesses and hospital officials said.

“The bomber came in through a side entrance in one tent. When he blew himself up, all I could see was dust and people being thrown back by the pressure of the blast,” said senior policeman Abbas Ali, who was off duty and among the mourners.

“It was chaos, we are still helping people out,” he said by telephone from the blast site.

Violence has fallen since the height of the war, but recent bombings on Shi'as are fuelling worries Iraq risks slipping back into major bloodshed, especially as the government's Shi'a, Sunni and ethnic Kurdish parties feud over sharing power.

Baquba, 65km northeast of Baghdad, is in Diyala province, once an al-Qaeda stronghold and one of the most volatile regions in Iraq with its mix of Sunni, Shi'a and Kurdish communities who dispute control of the area.

Iraq's al-Qaeda wing, the Islamic State of Iraq, has claimed recent attacks on Shi'a targets, as it tries to fuel sectarian tensions and undermine Shi'a Prime Minister Nuri al-Maliki's government.

Though weakened after years of war with Iraqi and American troops, the country's al-Qaeda affiliate and allied Sunni Islamists are still potent. At least one major attack has occurred each month in the six months since US forces left.

A suicide bomber detonated a car bomb outside a Shi'a religious office in Baghdad at the start of June, killing more than 20 people, and more than 75 were killed in bombings and attacks mainly targeting Shi'a pilgrims last week.

The latest attacks come as Maliki fends of attempts by Sunni, Kurd and some Shi'a rivals to organise a vote of no confidence against him. His opponents accuse the Shi'a leader of trying to consolidate his power at their expense. - Reuters