The nearly five-hour battle was in Paktia province that borders North Waziristan tribal district where the government signed a truce with pro-Taliban militants last month. The fight started when Afghan troops came under attack in the province's Barmal area on the border, the defence ministry told AFP.
"The result - 24 enemy were killed, their bodies were left at the site and we have carried them to our base," ministry spokesman General Mohammad Zahir Azimi said. "Among the dead there are Pakistan nationals, Chechens and people from other countries, as well as Afghans," he said.
Eight people were arrested alive, including three Pakistanis. A military commander reported earlier Tuesday that six Taliban and a soldier had been killed in a battle in Barmal. It could not be immediately confirmed if it was the same incident.
There is concern in insurgency-hit Afghanistan that the peace deal in North Waziristan has resulted in more militants crossing into the country to carry out attacks. The US-led coalition said last month it had seen a 300 percent increase in incidents in the area since a truce in North Waziristan was reached weeks before the September accord.
The accord saw the Pakistani forces scale down their presence in the area with the tribal leaders pledging to stop infiltration. In the southern province of Uruzgan, a US-led coalition airstrike killed a Taliban commander and up to 15 other militants in an early morning raid.
Coalition aircraft dropped three bombs on an insurgent compound soon after 1:00 am, the Nato-led International Security Assistance Force (ISAF) said in a statement. "The aircraft engaged a known mid-level Taliban commander... with three 500-pound bombs, killing him and 10 to 15 additional Taliban militants who had previously conducted ambush attacks on the Afghan National Army and ISAF," it said.
The separate ISAF and coalition forces together number about 40,000 troops. They carry out some of their operations together or with the Afghan security forces.