A man walks through the scene of a blaze started when a roadside bomb exploded in the predominantly Shiite area of Kazimiyah, sparking a fire in two discount clothing stores in Baghdad, Iraq today. No casualties were reported. The Iraqi government today declared a state of emergency and imposed a curfew as Iraqi and U.S. troops battled insurgents outside the heavily fortified Green Zone in Baghdad.

BAGHDAD, Iraq — The Iraqi government declared a state of emergency and imposed a curfew today after insurgents set up roadblocks in central Baghdad and opened fire on U.S. and Iraqi troops outside the heavily fortified Green Zone.

Prime Minister Nouri al-Maliki ordered everyone off the streets of the capital. U.S. and Iraqi forces also fought gunmen in the volatile Dora neighborhood in south Baghdad.

A car bomb ripped through a market and nearby gas station in the increasingly violent southern city of Basra, killing at least five people and wounding 18, including two policemen, police said.

A bomb also struck a Sunni mosque in Hibhib, northeast of Baghdad, killing 10 worshippers and wounding 15 in the town where Abu Musab al-Zarqawi was slain this month, police said.

At least 19 other deaths were reported in Baghdad.

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

Four Iraqi soldiers and three policemen were wounded in the fighting, police Lt. Maitham Abdul Razzaq said.

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

The prime minister's office said the curfew would last from 2 p.m. today until 6 a.m. Saturday but later shortened to end at 5 p.m. Friday.

The state of emergency includes a ban on carrying weapons and gives Iraqi security forces broader arrest powers, Defense Ministry official Maj. Gen. Abdul-Aziz Mohamed Jassim said.

"The state of emergency and curfew came in the wake of today's clashes to let the army work freely to chase militants and to avoid casualties among civilians," he said. "They will punish all those who have weapons with them and they can shoot them if they feel that they are danger."

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 also said two U.S. Marines were killed during combat in the volatile Anbar province in separate attacks on Wednesday and Thursday, and a soldier died elsewhere in a non-combat incident on Wednesday.