BAGHDAD, Iraq — Classes had just ended, children were milling outside and the elementary school's five male teachers had just gotten into a van to head home when the cars pulled up, full of men wearing Iraqi police uniforms.

But they weren't police. The nine gunmen — apparently Sunni insurgents — pulled the teachers and their driver from the van, while the school's few women teachers fled. They dragged the men into an empty classroom, lined them against the wall and gunned them down with automatic weapons.

The dead in yesterday's attack were all Shiite Muslims, the latest victims of the mounting sectarian killings in Iraq ahead of a crucial referendum on a new constitution that has sharply divided Sunnis and Shiites.

Most of the children in the teachers' classes at the Al-Jazeera Elementary School in the village of Muelha were Sunnis. Muelha, like many of the towns dotting the area south of Baghdad, has a mixed population of Shiites and Sunnis.

No children were hurt in the attack, which Iraqi officials said was the first of its kind to directly target schoolteachers.

"These men were terrorists wearing police uniforms," said Capt. Muthana Ahmed, director of the police force in Babil province.

Ahmed said the teachers and driver were Shiites from Hilla who shared a commute to the school in the village, near Iskandariyah. The area, known as the Triangle of Death, is one of the most dangerous in Iraq. Travelers who pass through on their way to southern Iraq routinely are stopped by insurgents manning illegal checkpoints. Shiites, government workers and people associated with the U.S. military often are killed on the spot.

Officials reported that 20 Iraqis and three U.S. soldiers were killed in other attacks around the country.

In Baqouba, 30 miles north of Baghdad, a suicide bomber attacked a group of Iraqis applying for jobs as policemen today, killing nine and wounding 21, a police officer said.

A man wearing explosives under his clothes blew himself up in a building where Iraqis were submitting applications to join the country's Quick Reaction Police Force.

In Baghdad yesterday, a suicide car bomber detonated a vehicle outside the compound of Iraq's Oil Ministry. The bomber rammed into a bus carrying employees of the ministry, killing seven police officers and three civil servants, said Col. Haitham Sami of the Interior Ministry.

The three U.S. soldiers were killed in two roadside-bomb attacks southeast and west of Baghdad. No further details were reported.

U.S. defense officials in Washington yesterday reported the killing over the weekend of a leading deputy to al-

Qaida's leader in Iraq, Abu Musab al-

Zarqawi. They identified the deputy as Abu Azzam. The officials spoke on condition of anonymity, citing the sensitivity of the information.

CBS News, quoting Pentagon officials, reported that U.S. forces killed Azzam in a house raid in Baghdad on Sunday. CBS described Azzam as al-Zarqawi's top deputy, in control of financing foreign fighters coming into Iraq.

It was unclear if Azzam was the same individual as a man whose name appeared in February on a U.S. list of the 29 most-wanted supporters of insurgent groups in Iraq. Sheikh Abdalluh Abu Azzam (aka Amir of Anbar) was listed as a Zarqawi lieutenant, with a $50,000 reward for his capture.

In the north, a top aide to al-Zarqawi surrendered to police in the city of Mosul, Iraqi army Brig. Gen. Ali Attalah said yesterday. The aide, Abdul Rahman Hasan Shahin, was one of the most-wanted figures in Mosul, Attalah said.

Attacks on the Shiite- and Kurdish-dominated interim government have increased in the run-up to the Oct. 15 referendum on a new constitution.

Other developments

• In Baqouba, gunmen assassinated Raad Hussein Jabar, a member of the Baqouba City Council. He was gunned down as he was leaving a market, a local doctor said.

• In the holy city of Najaf in southern Iraq, insurgents were able to penetrate the headquarters of the Kurdistan Democratic Party, planting a bomb that exploded inside yesterday. Raed Mousa, a KDP member in Najaf, said the blast collapsed part of the building and wounded three guards.

Compiled from The Washington Post and The Associated Press