Taliban gunmen shot dead the most high-profile female police officer in Afghanistan on Sunday as she left her home to go to work, officials and the militia said.

The attackers were waiting outside the home of Malalai Kakar, head of the city of Kandahar's department of crimes against women, and opened fire on her car, Kandahar government spokesman Zalmay Ayoobi told AFP.

"Today between 7.00am and 8.00am when she was (in her car) outside her house and going to her job, some gunmen attacked," Ayoobi said. "Malalai Kakar died in front of her house. Her son was wounded."

A doctor in the city's main hospital said Kakar, in her late 30s, had been shot in the head.

"She died on the spot and her son was badly injured and is in a coma," said the doctor, who declined to let his name be used.

A spokesman for the extremist Taliban movement, which targets government officials as part of an growing insurgency, said that the assassins were from his group.

"We killed Malalai Kakar," spokesman Yousuf Ahmadi told AFP. "She was our target, and we successfully eliminated our target."

Kakar, a mother of six, was regularly profiled in international media and was known for her courage in one of Afghanistan's most conservative provinces.

A captain in the police force and the most senior policewoman in Kandahar, she headed a team of about 10 women police officers and had reportedly received numerous death threats.

Kandahar is the birthplace of the extremist Taliban, who are mounting a growing insurgency that targets officials working with the government.

During their 1996-2001 hold on power, the Taliban stopped women from working outside the home and stopped them from leaving home without a male relative and an all-covering burqa.

Kakar was well-respected in the police force for her bravery, one of her colleagues said on condition of anonymity.

She was the first woman to enrol in the Kandahar police force after the 2001 ouster of the Taliban and had been involved in investigating crimes against women and children, and conducting house searches.

The head of Kandahar province's women's affairs department was killed in a similar way two years ago.

In June, gunmen shot dead a female police officer in the western province of Herat in what was believed to be the first assassination of a female police officer in the war-torn country.

Bibi Hoor, 26, was on her way home when two armed men on motorbikes opened fire, killing her instantly. It was not clear who killed her or why.

Afghanistan's police force was destroyed by the time the Taliban were removed and is being rebuilt with international assistance. It numbers about 80 000 people, including a few hundred women.

About 750 policemen have been killed in the past six months, mostly in insurgency-linked violence sweeping the country.