Thousands of people have protested in the streets of Basra, Iraq's second largest city, over lack of security.  Meanwhile, a mass grave has been found northeast of Baghdad containing about 100 decomposed bodies.  Daniel Schearf reports from the northern Iraqi city of Irbil.

People in Basra took to the streets Saturday, marching near police headquarters to protest poor security in the southern Iraqi city.

Residents complain that murder, kidnapping, and other crimes have increased since December when the British turned security over to Iraqi forces.

Rival groups have been fighting for influence in the predominantly Shi'ite city and were among those protesting.

Samir al Jazari is a member of the Badr Brigade, the military wing of a large Shi'ite party, the Supreme Islamic Iraqi Council.

Jazari says the group holds the central government in particular, and the local government, including the security leaders in Basra, responsible for killings and looting in the city.  He says the local police and security chiefs should do their jobs instead of being onlookers.

Also Saturday, Iraqi security forces found about 100 decomposed bodies in a mass grave near Khalis, a city in Diyala province northeast of Baghdad.  It was the largest mass grave discovered in months.

It was not immediately known who was responsible for the killings or when they occurred.  

Before the 2003 U.S.-led overthrow of Saddam Hussein, his government executed thousands of opponents, many of them Shi'ites and Kurds, and buried them in mass graves.

Human rights groups believe there are hundreds of mass graves in Iraq leftover from that time that have yet to be discovered. 

But, mass graves have become common in the post-Saddam era as well, as Shi'ite and Sunni militias battled for power.