Hundreds of insurgents launched a large-scale attack Tuesday against police in Afghanistan's remote Nuristan province, a part of the country that is largely controlled by the Taliban, officials said.

Provincial police chief Gen. Shams-ul Rahman Zahid said about 400 Taliban fighters were involved in the attack, which started after daybreak, targeting checkpoints around a base housing police reserve units located about 18 kilometres south of the provincial capital of Parun.

It's the second such large attack staged by the Taliban in less than four days and just one week after U.S. special forces killed al-Qaeda leader Osama bin Laden.

Over the weekend in the southern city of Kandahar, the birthplace of the Taliban and the economic hub of southern Afghanistan, the Taliban attempted a full frontal assault on government buildings across the city. At least two dozen insurgents, two members of the Afghan security forces and one civilian were killed in two days of fighting in Kandahar.

The Taliban have said the Kandahar attacks were planned well before bin Laden's death and were part of their spring offensive.

Zahid, the provincial police chief, did not say how many police were under attack or the size of the security force based in Nuristan although it is thought to be small.

"We have requested from NATO forces and the Afghan army to help. They have not responded yet. I have ordered other units to go and help," Zahid said. He gave no other details on the fighting but said it was ongoing.

NATO said it was not aware of the attacks. There are few coalition or Afghan Army troops in mountainous Nuristan, near the Pakistan border.

The Nuristan and Kandahar attacks are the most ambitious since the insurgents declared the start of a spring offensive against NATO and the Afghan government last month. NATO has been expecting the Taliban to stage a series of spectacular and complex attacks, and the group has already carried out a number of them.

Mohammed Zareen, a spokesman for the provincial governor, confirmed a large attack was under way but had no details on the number of insurgents involved. He said local residents were assisting the police.

"We have only national police in area. We don't have army or NATO forces to support police," he said.

Taliban spokesman Zabiullah Mujahid said Taliban fighters attacked police and that battles were under way.

"There are large attacks by Mujaheddin on four police checkpoints. Gun battles are going on," he said in a message sent to news organizations in Kabul.

The Taliban and other insurgent groups control large swaths of Nuristan, Kunar and other northeastern provinces near the Pakistani border. Insurgents retain safe havens in Pakistan's neighbouring lawless tribal regions and cross the border into Afghanistan to attack NATO troops.

Zahir said he had intelligence that the attacks were being carried out by Pakistanis and Arabs who have been crossing the border into Afghanistan.

The Taliban also control the tiny capital Nuristan's rugged Waygal district, which they overran with more than 300 fighters on March 29 and raised the white flag of the Islamic Emirate of Afghanistan, as the country was known when it was under Taliban control before the 2001 U.S. invasion.