Baghdad, Iraq ? Militants blew up 13 cars in three hours Sunday, injuring at least 20 people while 13 Iraqis were killed in other violence that fed the turmoil following last month’s contested parliamentary elections.

Sunni Arabs made their opening bid in what could be protracted negotiations to form a new government. Leaders of the minority’s main political group, the Iraqi Accordance Front, traveled to the northern city of Irbil for a meeting today with the president of the Kurdish region.

The Kurdish region in Iraq’s north already has seen a flurry of postelection bargaining between Kurds and the governing Shiite Muslim religious party, the United Iraqi Alliance.

Preliminary results from the Dec. 15 election have given the Shiite group a strong lead in the voting for Iraq’s 275-member parliament, but not enough for it to govern without other blocs.

Final election results are expected as early as this week.

The day’s worst bloodshed came in eastern Baghdad, where police said gunmen killed five people at a butcher shop and a bomb killed two police officers at a gas station.

Two more Iraqis were slain and five wounded by gunfire at a Sunni mosque in southern Baghdad, while a Shiite sheik was fatally shot at a market in the same part of the city.

In the northern city of Mosul, about a dozen gunmen attacked a police checkpoint, killing a bystander and wounding three policemen, police said.

Eight of the cars bombs exploded in Baghdad and wounded a total of 11 people, police said.

A suicide car bomber near Tikrit injured six civilians, and in the northern city of Kirkuk, a bomb aimed at an Iraqi police convoy wounded three civilians, police said. Car bombings in the northern city of Kirkuk and in Muqdadiyah caused no injuries.