BAGHDAD (Reuters) - At least seven people were killed when a suicide car bomber hit Iraq's interior ministry on Monday in the latest attack since a crisis erupted between the Shi'ite-led government and Sunni leaders a week ago.

Shi'ite Prime Minister Nuri al-Maliki sought the arrest of the Sunni vice president last Monday and asked parliament to fire his own Sunni deputy, triggering turmoil that threatens new sectarian strife just after the last U.S. troops withdrew.

The blast occurred when the bomber drove his vehicle into a security cordon outside the ministry in central Baghdad, detonating an explosion that left dead and wounded on the ground and set fire to nearby vehicles, police said. A senior police source said authorities believed insurgents were targeting the interior ministry because of the announcement of the arrest warrant for Sunni Vice President Tareq al-Hashemi, charged with running death squads.

Taped confessions of suspects the ministry said were Hashemi's bodyguards were aired on state-run Iraqiya television and other local media on Monday and linked the vice president to killings and attacks on Iraqi government and security officials.

"This is a direct message to us because we are the ones who arrested Tareq al-Hashemi's network and we are the ones who should preserve security in the country," said Ali al-Quraishi, a police lieutenant who monitors checkpoints around Baghdad.

The attack on Bab al-Sharji street followed a wave of explosions on Thursday, including one suicide car bomb and multiple roadside bombs, in mainly Shi'ite areas across the capital in which at least 72 people were killed. Seven people, including five policemen, were killed and 34 others, including seven policemen, were wounded in the attack on the interior ministry, police and hospital sources said.

"When I went outside I found my colleagues, some of them were killed, others were on the ground, many cars were burned, the policeman on the watchtower looked like he was killed when he was hit in the head," Zaid Raheem, a police guard, said. The ministry said in a statement that a suicide car bomber had attacked the entrance to its headquarters and killed 3 people and wounded 33.

Hashemi has left Baghdad for semi-autonomous Iraqi Kurdistan, where he is unlikely to be handed over to central government officials immediately.

The turmoil threatens to scuttle an uneasy power-sharing government that splits posts among the Shi'ite National Alliance coalition, the mostly Sunni-backed Iraqiya bloc and the Kurdish political movement.

A weekly cabinet meeting, expected on Tuesday, is seen as the key test for how the crisis develops, and tensions could rise further if government ministers from Iraqiya decide to boycott the meeting. Iraqiya lawmakers have already suspended their participation in parliament, which is in recess, though a statement from the party on Sunday said it was willing to take part in talks to try to solve the crisis.