Meanwhile, South Korea's foreign minister defended direct negotiations with the Taliban to free the hostages amid concern the move violated international principles and could spur more abductions.
Police attacked a group of Taliban late Friday who were planning to strike security forces in the central Afghan province of Ghazni, killing 18 and arresting six others, said provincial police Gen. Ali Shah Ahmadai.
Taliban fighters abducted 23 South Koreans in Ghazni district six weeks ago. They killed two male hostages, released two women last month and the final 19 were freed last week after the Taliban held unprecedented negotiations with the government in Seoul. They left Afghanistan Friday and were due in South Korea early Sunday.
South Korean Foreign Minister Song Min-soon on Saturday emphasized that South Korean negotiators were tasked with protecting the "innocent lives of hostages." He also denied claims that South Korea paid a ransom to the Taliban, saying "there is no such thing," according to Yonhap news agency.
South Korea drew praise at home for saving the remaining hostages, but many in the country are also concerned that its international reputation may suffer because of the direct talks—considered a breach of the widely accepted international principle of not negotiating with terrorists.
Further embarrassing Seoul, the Taliban have claimed that the kidnapping of the South Koreans were "successful" and vowed to continue with similar actions.
In southern Helmand province on Friday, a combined police and U.S.-led coalition patrol came under attack with mortar, rocket-propelled grenade and small-arms fire. In the fight that ensued, "almost two dozen" insurgents were killed, the coalition said in a statement Saturday.
No Afghan or coalition soldiers, or civilians, were killed, the statement said.
The fighting took place in Musa Qala district, parts of which have been under the control of Taliban fighters for several months.
U.S.-led troops and Afghan security forces also raided compounds late Friday in three villages in the remote Pitigal Valley border region, where intelligence showed that top fighter leaders take refuge as they travel between Pakistan and Afghanistan.
More than 20 insurgents were killed and 11 others were detained, while officers also discovered a bomb-making factory, the U.S.-led coalition said in a statement.
It was not possible to independently verify the death tolls in the three incidents because travel in the areas is extremely dangerous. Taliban commanders were not available for comment.
Last Mod: 01 Eylül 2007, 14:15
The Taliban ruled most of Afghanistan from the mid-'90s up until 2001, when they were ousted by a U.S.-led coalition following the Sept. 11 attacks.
They are now leading an increasingly bloody campaign against the country's Western-backed government. More than 4,200 people—most of them insurgents—have been killed this year alone, according to an Associated Press count.