The three car bomb explosions killed at least 15 people killed Monday in Iraq, including two attacks made against Iranian pilgrims, as political leaders met to end eight months of negotiations stalled over a new government.

Two of the bombs were aimed at Iranian pilgrims in Shiite holy cities of Kerbala and Najaf, killing at least 10 people, while the third struck a busy street of shops and restaurants in the oil center of Basra, a southern city Iraq, Reuters confirmed.

The Basra provincial subconsejero, Ahmed al-Sulaiti, and an Iraqi army source estimated the death toll in the explosion in Basra in five, with 42 wounded. The military source had indicated earlier that there were 12 deaths.

"The explosion was caused by a car bomb that killed five people and wounded 42" Sulaiti told Reuters, noting that the figures were original.

"This explosion is related to the bombings in Najaf and Karbala, and accuse these groups of Al Qaeda and the Baathists," he said.

A source at the Basra Operations Command said the blast came from a bomb in a truck. The police chief said the city was caused by a suicide bomber who had blown themselves up in a car.

Tensions are increasing in Iraq while the country remains in political limbo eight months after an election that failed to produce a winner.

While violence has fallen since the height of the sectarian war in 2006 and 2007, insurgents are still able to launch devastating attacks. More than 100 people died last week when gunmen took a church and several bombs exploded in predominantly Shiite areas in Baghdad.

U.S. troops are reducing their presence in Iraq before retiring completely next year.

Several Iraqis inspect the site where three car bombs exploded in the oil-rich city of Kirkuk.Meanwhile, seven people died and 34 were injured in an explosion in one of the entrances to Karbala, where one of the two holy shrines of Shiite Muslims, said Mohammed al-Moussawi, head of the Karbala provincial council. Four dead were Iranians, he said.

In Najaf, three people were killed and 10 wounded when a car bomb exploded near several buses carrying Iranian pilgrims to the shrine of Imam Ali, according to a hospital.

A police source put the number at five dead and 16 wounded and said most of the dead were Iranians.

Another officer of the health office in Najaf said eight people, including three Iranians killed in the explosion, and that 19, seven of them Iranians, were injured.

Hundreds of thousands of Iranian religious tourists have visited Shiite holy sites in neighboring Iraq since the US-led invasion in 2003 toppled Saddam Hussein. Android app