A homicide car bomb exploded next to a NATO convoy in southern Afghanistan Sunday, and troops speeding away from the scene shot at several civilian cars. Three Afghans were killed in the chaotic violence, while 19 people were wounded, including three NATO soldiers, officials said.

The blast damaged an open-top NATO vehicle and scattered the pieces of the car bomb over a wide area in Kandahar city. Three NATO soldiers were wounded, said Squadron Leader Jason Chalk, an alliance spokesman in Kandahar. He did not disclose their nationality.

The homicide bomber tried to ram his car into the convoy as the troops were driving through the city, said Razaq Khan, a police officer at the scene.

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Two civilians were killed and 10 wounded in the blast, said Dr. Bashir Ahmed of the main Kandahar hospital.

A Taliban spokesman claimed responsibility for the attack.

After the explosion, soldiers speeding from the scene fired at civilian vehicles. An Associated Press reporter saw soldiers fire on cars about a kilometer (a half mile) from the blast site, including a man on a motorcycle who was shot in the stomach.

Ahmed said six Afghans were wounded by the gunfire.

Zarar Ahmad Muqbal, Afghanistan's interior minister, told a news conference in Kabul that one civilian was killed and one was injured by the gunfire. He was apparently describing only one car that was hit.

Maj. Luke Knittig, the spokesman for NATO's International Security Assistance Force, said as the patrol was driving away from the blast site it came across a suspicious car soldiers feared might be a second homicide bomber — apparently the car Muqbal spoke of.

Knittig also said there might have been a "wider engagement" of gunfire in the immediate aftermath of the blast. Chalk said the patrol fired warning shots to keep people away and that some civilians may have been injured as a result.

Isah Mohammad, one of the Afghans injured by gunfire, said from his hospital bed that he was driving through Kandahar with his cousin when the convoy passed them.

"The convoy was coming and there was some gunfire, but I thought it was a wedding ceremony," said Mohammad, who is in his early 30s and was hit in the shoulder and the right leg. "When they got closer, they started shooting at us."

His uncle, Gahfoor Aqa, had harsh words for NATO troops. "They were going to the shop and they are hit by bullets from NATO, who are always saying they're coming to rebuild our country. But instead they are shooting our children," he said.

The blast was the fourth homicide attack in the Kandahar region in a week. Two Canadian soldiers were killed last Monday by a homicide car bomb just outside Kandahar.

A Taliban spokesman, Qari Yousef Ahmedi, claimed responsibility for Sunday's attack.

Taliban insurgents have launched a record number of homicide attacks in Afghanistan this year. The bombs typically target NATO and Afghan security forces but more often kill civilians. NATO figures as of last week showed that 227 Afghans and 17 international soldiers have been killed in about 105 suicide bombings this year.

Meanwhile, militants attacked a NATO convoy in neighboring Helmand province's Nawzad district on Sunday, said Ghulam Nabi Malakheil, the province's police chief.

NATO-led troops fired back and called in airstrikes that left five militants dead, he said. Police recovered militants' bodies following the clash, he said.

In Zabul province, suspected Taliban militants attacked a police checkpoint, sparking a gunbattle that left four insurgents dead and one police officer wounded, an official said.

The early morning clash occurred near Qalat on the main highway linking Kabul and Kandahar, said Jailany Khan, Zabul's highway police commander.

Afghanistan's south is the center of a revived Taliban insurgency that this year alone has left over 3,700 people dead.

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