Taliban insurgents publicly flogged and executed an Afghan woman for alleged adultery, Afghan police said.

The 48-year-old widow was given dozens of lashes before being shot dead.

The incident happened on Sunday in the remote Qades district held by militants in northwestern Badghis province, said Abdul Jabar, a senior provincial police officer.

"It happened before the public ... Although no-one has complained, the government will take its own measures about the incident," Jabar said.

A statement issued by the NATO-led International Security Assistance Force (ISAF) said "according to reports" the woman was pregnant and was whipped 200 times before she was shot by a Taliban commander.

However, Qari Mohammad Yousuf, the main Taliban media spokesman, said the group was not behind the Qades execution.

The unidentified man who had the alleged affair with the woman had escaped, Jabar said.

The Taliban on one side and the Afghan government and foreign forces on the other are engaged in a propaganda battle to win the hearts and minds of Afghan civilians.

When in power from 1996 until 2001, the Taliban staged public stonings or lashings of Afghans found to have had sex outside marriage.

The Taliban denied responsibility after Time magazine published a cover photograph last month of a young Afghan woman who said her nose was cut off as punishment for fleeing abuse at her husband's house.

If confirmed, Sunday's execution would be the second of a woman by the Taliban since they were ousted by U.S.-backed Afghan forces nine years ago. A woman was previously executed for alleged spying for foreign forces.

One such execution, of a woman wearing an all-encompassing burqa and shot as she knelt in the Olympic Stadium in Kabul, caused outrage when film of the incident was leaked.

The judiciary in neighbouring Iran last month suspended a sentence of death by stoning for a woman convicted of adultery after an international outcry over the case.