A Sunni cleric known for denouncing insurgents in Iraq was killed Friday by a bomb that ripped apart his car, a police official said, in the second targeted attack on a religious figure in as many weeks.

Activists and clerics who speak out against Al Qaeda in Iraq and other insurgent groups have been attacked with some regularity, raising the possibility that the waning insurgency has shifted to a more targeted terror campaign.

Jamal Humadi was driving home after delivering his Friday sermon in Saqlawiyah, 45 miles northwest of Baghdad, when a bomb attached to his car exploded, the official said. Two passengers were wounded.

Humadi was known for his opposition to Al Qaeda and Sunni extremists, routinely calling on worshippers to turn away from the sectarian violence that engulfed the country two years ago.

Last week, Sunni cleric Bashir al-Juheishi was killed by a bomb attached to a car — known as a sticky bomb — in Mosul as he left a mosque there.

Al-Juheishi was also known for taking a stand against Al Qaeda in Mosul, a city the U.S. military has called the last urban stronghold of the group.

Insurgents carrying out such targeted attacks are using booby-trapped cans of food and toys, the military spokesman for Baghdad security warned on Friday.

"Booby-trapped cans are being used to carry out assassinations because they can be used as sticky bombs," said Maj. Gen. Qassim al-Moussawi. "They can be easily attached to any car or bus to target specific people."

Al-Moussawi issued the warning on a government Web site, saying Iraqi security forces found a small bomb-making facility in western Baghdad with explosive-laden cans and toys.

Security forces discovered toy guns packed with explosives at the factory, he said.

Al-Moussawi said troops were also alert to the possibility that insurgents could attempt to mobilize children to carry out attacks, though there have been no recent reports of teens attacking security forces.

Earlier this year, the U.S. military said it seemed insurgents were recruiting teenagers between the ages of 14 and 19 for grenade and suicide attacks.

The military has frequently said it believes Al Qaeda in Iraq and other insurgent groups are recruiting children and women because they can more easily evade security measures.

Elsewhere, Iraqi police accompanied by American military advisers arrested two men suspected of making and distributing explosives vests throughout Iraq to be worn by suicide attackers, the U.S. military said in a statement Friday.

Forces raided his home in Duluiyah, 45 miles north of Baghdad, the statement