BAGHDAD, (Reuters) – A suicide bomber driving a truck packed with explosives hit a police station in central Kirkuk on Wednesday and residents reported many casualties in further violence after one of the bloodiest days in months.

A police source said three bodies had been found so far and there were 38 wounded, most of them critically. “There are still people under the rubble of the houses,” the source said.

On Tuesday bombers killed 70 people, many of them young women students, at a Baghdad university.

In all, at least 105 were killed in bombings and a shooting in the capital on a day when the United Nations said more than 34,000 Iraqi civilians died in violence last year. Four U.S. soldiers were killed in a bomb attack in northern Iraq.

A police source said many buildings in the area bombed in Kirkuk on Wednesday suffered severe damage from the blast and rescuers were still searching for victims.

One resident told Reuters he saw many casualties lying in the street and several buildings collapsed.

Just outside the borders of the largely autonomous Kurdistan region, Kirkuk’s population is a volatile mix of Kurds, Turkmen and Sunni and Shi’ite Arabs.

The United Nations warned on Tuesday of a “looming crisis” there amid growing tension between the different ethnic groups. The northern city also sits atop one of the world’s richest oil fields.

Iraqi security forces are frequently targeted by bombers seeking to undermine the U.S.-backed Iraqi government. Police in many areas are also infiltrated by militias, making them a target for rival armed groups.

The Shi’ite prime minister blamed Tuesday’s bombing at Mustansiriya University on followers of Saddam Hussein. His fellow Sunni Arabs are angry at the botched execution of two aides on Monday, two weeks after the ousted leader was himself hanged to sectarian taunts from official observers, captured on an illicit video.

Among extensive coverage of reaction to the executions was widely played footage of interviews with students at Mustansiriya who were celebrating the hangings.

The United Nations, in its latest two-monthly human rights report on Iraq, said data from hospitals and morgues put the total civilian death toll for 2006 at 34,452 — 94 each day.

The Iraqi government is preparing a security crackdown in Baghdad, involving Iraqi and about 20,000 American reinforcements, which is widely portrayed as a last chance to avert a civil war between Sunnis and Shi’ites that could draw in Shi’ite Iran and Arab states on opposing sides.

U.S. Secretary of State Condoleezza Rice wound up her visit to the Gulf on Wednesday after winning support from Arab allies for U.S. plans to deploy 20,000 more troops in an effort to stabilise Iraq.

Gulf countries, particularly Saudi Arabia, said however that the Shi’ite-led Iraqi government also had to play a role in curbing sectarian violence and that the Shi’ite militias blamed for sectarian killings must be disbanded.