Baghdad - A nephew of Saddam Hussein serving a life sentence for financing insurgents and possessing bombs escaped from prison Saturday in northern Iraq with the help of a police officer, authorities said.

Special coverage: Iraq after War Related readings: Saddam appears at genocide trial "Rumsfeld replacement is agent of change" Bush taps Gates to replace Rumsfeld Rumsfeld out, ex-CIA chief Gates in

Sectarian attacks killed at least 20 people, including five who died in a suicide car bombing outside a Shiite shrine in Karbala, police said. Officers also found 39 bullet-riddled bodies in Baghdad that apparently were victims of revenge killings by Sunni Arabs and Shiites.

The escape by Saddam's nephew underlined one of the problems facing the US military as it tries to train enough Iraqi security personnel so US troops can go home: the ability of Sunni Arab insurgents and Shiite militiamen to infiltrate Iraqi police forces.

Ayman Sabawi, son of Saddam's half brother Sabawi Ibrahim Hassan al-Tikriti, escaped from a prison 45 miles west of the northern city of Mosul in the afternoon with the help of a policeman, said a local police commander, Brig. Abdul Karim al-Jubouri.

Brig. Abdul-Karim Khalaf, an Interior Ministry spokesman, confirmed the escape but declined to discuss any details.

Sabawi, who was arrested in May 2005 by US and Iraqi forces near Saddam's hometown of Tikrit, 80 miles north of Baghdad, was convicted of illegally crossing the border from Syria and sentenced to 15 years in prison late last year by an Iraqi court. He was sentenced to life in prison in an earlier case for possession of illegal weapons and manufacture of bombs.

He "played a particularly active role in sustaining the terrorism by providing financial support, weapons and explosives to terrorist groups," Iraq's government said.

In July 2005, the United States froze Sabawi's assets along with those of five other Saddam nephews, accusing them of providing funds to Iraq's Sunni Arab-dominated insurgency.

Sabawi's father was captured in February 2005. Formerly the head of Saddam's intelligence service, al-Tikriti was No. 36 on a US list of the 55 most-wanted members of Saddam's ousted regime.

The suicide bomb attack occurred near the Al-Abbas shrine in Karbala, a Shiite holy city 50 miles south of Baghdad.

The shrine's golden dome and minarets didn't appear damaged in video shown on Iraqi state TV, but the blast set many parked cars on fire in a nearby street. Two men with bloody faces could be seen running through heavy black smoke past the body of another victim.

A main goal of Sunni Arab insurgent groups such as al-Qaida in Iraq has been to spark sectarian violence by attacking sites revered by the country's Shiite majority.

In Baghdad, some of the worst violence was in a Sunni pocket of Hurriyah, a mixed neighborhood. Witnesses said Shiite militiamen entered the area after Sunnis warned the few Shiites living there to leave or be killed. Heavy machine gun fire was heard and three columns of black smoke rose into the sky, the witnesses said on condition of anonymity out of concern for their own safety.

Mohamed al-Askeri, a Defense Ministry spokesman, said some people were chased from their homes, but Iraqi security forces drove off the attackers, handed out food to displaced people and persuaded most to return to their homes. But "others are still frightened," he said.

Adnan al-Dulaimi, who heads a large Sunni bloc in Parliament, went on a Sunni-run TV station to demand protection for the district's Sunnis. "We appeal to the government and US forces to rescue Sunni families in Hurriyah who are facing killings and displacement by militias."

The US military, meanwhile, announced that two Marines were killed in combat in Anbar province, raising to 42 the number of US troops who have died in Iraq this month. At least 2,930 have died since the Iraq war started in March 2003.

Iraq's influential Association of Muslim Scholars and the country's largest Sunni Arab political party, the Iraqi Islamic Party, on Saturday condemned a deadly US military attack the previous day in al-Ishaqi village in volatile Salahuddin province.

The US command said a ground raid and airstrike killed 20 insurgents, but local officials claimed at least 19 civilians died, including seven women and eight children.

About 1,000 residents of the predominantly Sunni village of al-Ishaqi held a funeral for the 19 dead Saturday, shouting "Down with the occupiers," "Long live the resistance," and "There is no God but Allah."

The Association of Muslim Scholars, a group of hard-line Sunnis that opposes the coalition, issued a statement alleging US soldiers entered two Iraqi houses, shot 32 civilians to death, including women and children, and then blew up the buildings to make it look as if the victims died in a US airstrike targeting insurgents.

The Iraqi Islamic Party, part of a Sunni bloc that controls 44 of parliament's 275 seats, made a similar claim, calling the attack "a new massacre by the American occupiers."

Last spring, a US investigation cleared American soldiers of misconduct during a March 15 raid in al-Ishaqi in which Air Force planes destroyed a building believed to be hiding al-Qaida in Iraq insurgents. Villagers claimed soldiers killed 11 civilians before ordering for the airstrike.