Iraqi officials said Monday that eight pro-government, anti-al Qaeda Sunni militiamen were kidnapped and killed by gunmen north of the capital, Baghdad, the latest in a series of bold insurgent attacks to hit the country in recent months.

The men were snatched from their houses in the town of Mishahda and surrounding villages during the past two days, a police officer said.  He added that their dead bodies were left in an orchard on Monday with gunshot wounds to their heads and chests. Some had their hands bound behind their backs.

The government-allied militiamen, or Sahwa, joined forces with U.S. troops to fight al Qaeda. They are a frequent target for al Qaeda in Iraq, which considers them traitors. The town, a former insurgent stronghold, is 20 miles north of the capital.

A health official confirmed the casualty figure. Both officials spoke on condition of anonymity as they were not authorized to release information.

Also Monday, the United Nations mission to Iraq said last month violence claimed the lives of 761 Iraqis and wounded 1,771 others. The statement said the worst-affected province was Baghdad with 258 people killed and 692 injured. It was followed by Salahuddin, Ninevah, Diyala and Anbar provinces in central and northern Iraq.

Violence increased sharply in April and May, with frequent bombings in civilian areas raising fears that widespread sectarian conflict may once again break out in the country. The bloodshed accelerated after a deadly April 23 crackdown by security forces on a Sunni protest in the northern town of Hawija.