BAGHDAD (AP) – A parked car exploded near a hospital in Baghdad’s main Shiite district on Saturday – the deadliest in a series of bombings that killed at least nine people and wounded dozens in Iraq, police said.

The blast in Sadr City occurred about 10:30 a.m. and was targeting street vendors and pedestrians just outside the entrance to the al-Sadr General Hospital. Police said at least five people were killed and 15 wounded.

A plume of black smoke rose from the scene while firemen sprayed water on smoldering cars.

The attack came two days after a double suicide attack struck a market in the nearby Shiite Shaab neighborhood, killing at least 82 people on one of the deadliest days since the war started four years ago.

Another parked car bomb struck a gas station about 9:30 a.m. in the Shiite city of Hillah killing at least two people and wounding 22, provincial police said. The city, 60 miles south of Baghdad, has been the site of some of the deadliest blasts since the war started four years ago, including a double suicide bombing against a crowd of Shiite pilgrims that killed 120 people on March 6.

In northern Iraq, a car exploded about 7 a.m. after the driver parked it near Iraqis looking for work in the center of Tuz Khormato, 130 miles north of Baghdad.

The driver and two workers were killed and 11 others wounded in the attack, police Colonel Abbas Mohammed Amin said. He said the driver intended to wait until more workers had gathered before detonating the explosives but they went off prematurely, preventing a higher casualty toll.

The attacks raised to at least 517 the number of people killed in the past seven days as suicide bombers and militiamen fought back ferociously despite an American-Iraqi security sweep that is in its seventh week.

The American military, meanwhile, denied that it was involved in airstrikes over Sadr City on Friday after local officials said 20 suspected militants were killed and 14 others wounded, along with seven civilians, in an airstrike targeting a Shiite militant base in eastern Baghdad.

President Bush, the American military and American diplomats in Iraq have expressed cautious optimism about the crackdown on violence that began Feb. 14 in Baghdad, Anbar province and regions surrounding the capital, but the ease with which suspected Al Qaeda suicide bombers have continued striking Shiite targets has cast a shadow over the effort.

Only about a third of the additional 30,000 soldiers and Marines that Mr. Bush pledged for the security drive are in the country, with the full deployment not expected until June.

The government on Friday vowed it would win the race against terrorism and despair.

“There is a race between the government and the terrorists who are trying to make people reach the level of despair,” al-Maliki adviser Sami al-Askari said. “But the government is doing its best to defeat terrorists and it definitely will not be affected by these bombings.”

Radical Shiite cleric Muqtada al-Sadr blamed the United States for the violence and called for a huge anti-American demonstration April 9, the fourth anniversary of the fall of Baghdad.

Mr. al-Sadr’s statement was his first since March 16, when he urged supporters to resist American forces through peaceful means. American and Iraqi officials say al-Sadr remains in Iran, sitting out the security crackdown, but aides have told The Associated Press he has returned to Najaf.

His latest declaration was read to worshippers during Friday prayers at a mosque in Kufa, a twin-city to Najaf where al-Sadr frequently led the ritual, and in Baghdad’s Sadr City Shiite enclave.

“I renew my call for the occupier to leave our land,” he said in the statement, a copy of which was obtained by AP. “The departure of the occupier will mean stability for Iraq, victory for Islam and peace and defeat for terrorism and infidels.”

Mr. al-Sadr, whose Mahdi Army militiamen fought American troops in 2004 but have generally cooperated with the current American-Iraqi security push in Baghdad, blamed the presence of U.S. forces in Iraq for the rising violence, lack of services and sectarian bloodshed.

“You, oppressed people of Iraq, let the entire world hear your voice that you reject occupation, destruction and terrorism,” he said in calling for the April 9 demonstration.