Hundreds of Afghan troops are searching for Taleban fighters hiding in the mountainous region of the Zabul province, the region's governor has said.
Zabul Governor Hamidullah Khan Tokhi said the operation, in mountains about 200 kilometres (125 miles) north-east of the southern city of Kandahar, follows several days of heavy fighting between government troops and up to 200 fighters from the ousted Taleban regime.
"We are trying to arrest these Taleban alive," he told the Associated Press news agency.
"Many of them are very young."
The province's deputy governor told French news agency AFP that local villagers reported the appearance of Taleban soldiers in the area on Friday.
Ten Taleban soldiers were killed in last week's fighting and 12 were injured, with a further 22 arrested.
An Afghan commander was also killed, the regional governor said.
Khalid Pashtoon, spokesman for Kandahar's governor, told the BBC that Taleban fighters were coming over the border from Pakistan.
And Afghan Interior Minister Ali Ahmed Jalali said at a news conference on Thursday that some of the young Taleban arrested said they were encouraged by a teacher at their school in Chaman, Pakistan, to come over the border to fight for the Taleban.
'Increase in attacks'
Operations to rout remnants of Afghanistan's former Taleban regime and members of Osama Bin Laden's al-Qaeda network by both Afghan troops and US forces have continued since the US-led conflict in Afghanistan in 2001 ousted the regime.
Last month Britain also announced it was to send additional troops to the country to help its newly-formed government maintain control over local warlords.
However the head of the country's peacekeeping International Security Assistance Force (ISAF) said on Wednesday that attacks across the country by Taleban and al-Qaeda fighters had doubled between April and May and were still at a high level.
"What we realised and what we recognised over the last four or five months is really an increase of incidents and accidents in the entire country," German Lieutenant General Norbert van Heyst said.