Taleban fighters have seized local government offices in Afghanistan's south-eastern province of Zabul.
Taleban fighters in Zabul 'want the Americans out'
A local spokesman said police in Khan Afghan district had withdrawn because they did not have enough ammunition.
Meanwhile, in Helmand province the Taleban are reported to have been forced out of the town of Sangin by Nato and Afghan troops.
President Hamid Karzai says his government has been having meetings with the Taleban for "a long time".
In fresh violence on Friday, a suicide bomber has killed six people near parliament in the capital, Kabul.
The Taleban have been forced out of the town of Sangin in Helmand province, the governor of Helmand told the BBC.
Brigadier Jerry Thomas, the commander of the UK taskforce in Helmand, said: "The aim of this operation was to clear the Taleban from the Sangin area and re-establish the authority of the government of Afghanistan in Sangin to create a secure, stable and prosperous environment in which reconstruction and development can take place.
"In the last two days we have made significant gains in pushing the Taleban from the area and that operation continues," he said, quoted by the Press Association (PA).
According to PA, the operation began on Wednesday night and involved more than 1,000 troops, including 42 Commando Royal Marines battle group, an Estonian armoured infantry company and elements from a Danish reconnaissance unit.
Chinook, Black Hawk and Apache helicopters were used to support the mission, reports said.
Nato said it airlifted hundred of troops into the area earlier this week as part of Operation Achilles, aimed at "our long-term goal of providing the security conditions necessary to allow the government of Afghanistan to begin reconstruction and development in the area".
It said it has inflicted serious damage to the Taleban's infrastructure in the area.
Car blown up
Meanwhile, in the capital Kabul, President Karzai told journalists that the number of people killed in a suicide attack on Friday near parliament had risen.
"Six of our countrymen were martyred in this incident," he said. They include at least one policeman.
The bomber blew himself up in his car when approached by police, officers at the scene were quoted as saying.
The Associated Press news agency quoted a witness, Samiullah Ahmad Rahim, as saying that he heard a big explosion and saw a large fireball shortly after the blast.
Reports said the debris from the blast littered the road. Window panes from a nearby building shattered.
The aftermath of Friday's Kabul suicide attack
There has been no claim of responsibility for Friday's attack. But the Taleban says it has hundreds of fighters prepared to carry out suicide attacks.
Last week four people died in a blast near Kabul's main market during the morning rush hour, in one of a series of attacks in recent weeks.
In his comments to the press, Mr Karzai also said official contacts with the Taleban were well established.
"We have had representatives from the Taleban meeting with different bodies of Afghan government for a long time.
"I have had some Taleban coming to speak to me as well."
Last year saw the worst fighting in Afghanistan since coalition troops ousted the Islamist Taleban from power in 2001.