The Iraqi government announced plans Tuesday to shorten the curfew in the capital by two hours, saying security had improved enough to let residents stay on the streets until 10 p.m.

Brig. Gen. Qassim al-Moussawi, the spokesman for the Baghdad security operation, said the curfew had been shortened "because the security situation has improved and people needed more time to go shopping."

Since the latest security operation began on Feb. 14, the military had enforced a 8 p.m. to 5 a.m. curfew. Before the joint U.S.-Iraqi crackdown, curfew had been from 11 p.m. to 5 a.m.

Violence in the capital has decreased rapidly since the nearly 7-week-old neighborhood-by-neighborhood sweep to quell sectarian violence in the capital began.

On Sunday, a congressional delegation led by Sen. John McCain, guarded by 100 U.S. soldiers and two Apache attack helicopters, toured a Baghdad market in a visit he said showed security had improved in the capital.

But Karim Abdullah, a 37-year-old textile merchant in the Shorja market, said the congressmen were kept under tight security and accompanied by dozens of U.S. troops.

"They were laughing and talking to people as if there was nothing going on in this country or at least they were pretending that they were tourists and were visiting the city's old market and buying souvenir," he said. "To achieve this, they sealed off the area, put themselves in flak jackets and walked in the middle of tens of armed American soldiers."

A senior U.S. military official in Baghdad said about 100 American soldiers were part of the security contingent but most of them stayed behind with the vehicles, estimating that no more than 20 troops went with the congressmen as they roamed the streets of the market, which has been hit by several recent bombings, including a February attack that killed 137 people.

The official, who accompanied the congressman on the market visit but spoke on condition of anonymity while discussing security arrangements, said Iraqis were not kept from approaching the dignitaries. Access to the market was closed to vehicles as part of a daily ban during business hours to prevent car bombs. He said sharpshooters were likely on nearby roofs and two Apache attack helicopters flew overhead, but said that was not unusual for visiting dignitaries.

The official said the congressmen had flown from the Green Zone in helicopters to a forward operating base in Baghdad, then traveled in Humvees to the market, getting stuck in traffic at one point. They then visited a U.S.-Iraq joint security station in the predominantly Shiite Karradah neighborhood, one of Baghdad's safest.

Jaafar Moussa Thamir, a 42-year-old who sells electrical appliances at Shorja, said the delegation greeted some fellow vendors with Arabic phrases but he was not impressed.

"They were just making fun of us and paid this visit just for their own interests," he said. "Do they think that when they come and speak few Arabic words in a very bad manner it will make us love them? This country and its society have been destroyed because of them and I hope that they realized that during this visit."

McCain, a Republican presidential hopeful who was a prisoner of war in Vietnam, appeared at a news conference shortly after the market visit to say it was proof that security was improving in the capital.

He acknowledged a difficult task lies ahead in Iraq, but he insisted the U.S.-Iraqi security plan was working, citing a recent drop in execution-style sectarian killings, the establishment of security posts throughout the city and Sunni tribal efforts against Al Qaeda in the western Anbar province.

"These and other indicators are reason for cautious, very cautious optimism about the effects of the new strategy," McCain said.

At least eight people were killed in scattered violence Tuesday, a day after a suicide truck bomber with explosives hidden under bags of flour crashed into a police station in a Kurdish neighborhood in the disputed oil-rich city of Kirkuk, killing at least 15 people, including a newborn girl and a U.S. soldier, and wounding nearly 200.