Iraqi authorities say a series of bombings in Baghdad has killed 16 people and wounded more than 40 others, many of them Shi'ite pilgrims traveling to the holy city of Karbala for an annual ritual.

In one of Monday's attacks, a car bomb killed eight people in a western part of the Iraqi capital, while another car bomb killed six people in the northern Shi'ite district of al-Shaab. Earlier, a roadside bomb in southern Baghdad killed two people.

Authorities say the attacks appeared to target Shi'ites heading south through Baghdad on the way to Karbala for the observance of Arbaeen, the end of a 40-day mourning period for a revered Shi'ite figure, Imam Hussein.

Insurgents attacked Iraqi Shi'ites last Thursday in a wave of bombings that killed at least 72 people in Baghdad and the southern city of Nasiriyah.

The escalation of violence against Iraq's majority Shi'ites coincides with a political crisis in the country's Shi'ite-led unity government, which has seen its main Sunni-backed faction, Iraqiya, boycott the Cabinet.

Iraqiya accuses Shi'ite Prime Minister Nouri al-Maliki of monopolizing power in Shi'ite hands. It also objects to a government arrest warrant for Iraq's Sunni Vice President, Tarek al-Hashemi, a member of Iraqiya.

Mr. Maliki has ordered Hashemi's arrest on charges of running a death squad, an allegation the vice president denies. The Iraqi prime minister issued the arrest order last month, as U.S. troops completed a pullout from Iraq, ending an eight-year military presence.

Hashemi fled to northern Iraq's autonomous Kurdish region to avoid arrest. In an interview with VOA's Kurdish service on Monday, Hashemi said he is ready to stand trial in the northern Iraqi city of Kirkuk, where he believes he can have a fair hearing. Kirkuk is located outside of Iraqi Kurdistan.

Hashemi said he refuses to accept the government's demand to stand trial in Baghdad because he believes politicians will manipulate the proceedings there.