Throughout the morning Friday, Iraqi and U.S. military forces clashed with attackers who were armed with rocket-propelled grenades, hand grenades and rifles in busy Haifa Street that runs into the Green Zone, site of the U.S. and British embassies and the Iraqi government.

Two Iraqi soldiers and a policeman were wounded in the fighting, said police Lt. Maitham Abdul Razzaq said.

The region was sealed and Iraqi and U.S. forces conducted house-to-house searches.

Gunmen also attacked a group of worshippers marching from Sadr City, the Shiite slum in eastern Baghdad, to the Buratha mosque on the other side of the city to protest a suicide attack a week ago on the revered Shiite shrine. At least one marcher was killed and four were wounded, Lt. Ahmed Mohammed Ali said.

The U.S. military on Friday said a Marine had died in combat and a soldier was killed in an unspecified non-hostile incident three days earlier. Their deaths raise to at least 2,514 members of the U.S. military who have died since the Iraq war started in March 2003, according to an Associated Press count.

The new security measures came as Prime Minister Nouri al-Maliki sought to rein in unrelenting insurgent and sectarian violence. He launched a massive security operation in Baghdad 10 days ago, deploying tens of thousands of troops who flooded the city, snarling traffic with hundreds of checkpoints.

While violence had diminished somewhat, the outbreak of fighting on Haifa Street and in the Dora neighborhood apparently prompted al-Malaki to declare the state of emergency even as Friday prayer services were in progress, sending many residents scrambling homeward to beat the curfew.

Also Friday, police said they found the bodies of five men who apparently were victims of a mass kidnapping from a factory on Wednesday. The bodies, which showed signs of torture and had their hands and legs bound, were floating in a canal in northern Baghdad, police Lt. Maitham Abdul-Razzaq said.

Meanwhile, the U.S. military said it killed four foreign insurgents in a raid north of Fallujah. Two of the dead men had 15-pound suicide bombs strapped to their bodies. The military said an insurgent thought to be an Iraqi also was killed in the raid, which was launched on information from a suspected arrested in the region in previous days.

Separately, the military said, it detained a senior leader of al-Qaida in Iraq and three other suspected insurgents Monday during raids northeast of Baghdad, near where al-Qaida chief Abu Musab al-Zarqawi was killed in a U.S. air raid earlier this month.