An official has said Taliban insurgents ambushed a convoy of Afghan security forces in a mountainous area of northern Afghanistan on Monday, killing 22 soldiers and police.
The Taliban fighters attacked from the mountains as the convoy was travelling through Laghman Valley in Sar-e-Pul province, Gov. Abdul Jabar Haqbeen said. "Twelve army and police vehicles are totally destroyed," Haqbeen said.
Eight security forces were wounded and seven were taken captive by the insurgents.
David Cameron has told ITV News Britain has paid a "very high price" in Afghanistan as he made his last visit to the country before British troops leave.
Speaking to International Affairs Editor Rageh Omaar, the Prime Minister said: "The most poignant memory has always been looking at the names inscribed on the wall and seeing those who have fallen, and recognising that we have paid a very high price."
Mr Cameron ruled out sending British troops back to Afghanistan if the country's government could not meet future security challenges, insisting Britain had "trained up an efficient and effective" Afghan national army and police force.
Prime Minister David Cameron has been addressing British troops in Camp Bastion, Afghanistan, to thank them for their sacrifice and service during the 13-year military campaign.
As those at Camp Bastion prepare to go home, he pledged to support those injured in the conflict, and paid tribute to the 453 who "paid the ultimate price" for the future of Afghanistan.
David Cameron has ruled out sending British troops back to Afghanistan, even if security in the country deteriorates.
The Prime Minister said: "We're not going to send combat troops back to Afghanistan because we have trained up an army...to provide that security that Afghanistan needs and we also need in our country."
He added that the "build up" of the Afghan national security forces was the "absolute priority".
David Cameron said Britain had paid a "heavy price" for its involvement in Afghanistan.
Speaking at a press conference with Afghanistan president Ashraf Ghani, the Prime Minister said Britain would continue to help the country and will be "training officers which will form the backbone of the Afghan army".
Mr Ghani thanked the families of British troops who lost their lives in the conflict, saying "they stood shoulder-to-shoulder with us".
He added: "Your presence here has meant that London has been safe, as well as the rest of the world."
David Cameron said the Taliban must give up violence and join the political process if they wish to have a voice in Afghanistan.
The Prime Minister, who is in Kabul speaking at a press conference with the country's new president Ashraf Ghani, said it was "striking" how far Afghanistan's security forces have come in recent years.
He said the country "would always have a strong partner" in the UK and that he was "immensely proud" of the role British troops played in Afghanistan.
Britain's armed forces have paid a "very high price" for their involvement in Afghanistan, David Cameron acknowledged, as he flew in for talks with the country's new leaders.
With the UK drawing to the close of its 13-year military involvement in the country, the Prime Minister said that Britain had gone "a long way" towards achieving its objectives there.
Mr Cameron was meeting newly installed president Ashraf Ghani - who took office just four days ago - and chief executive Abdullah Abdullah.
The Prime Minister also paid tribute to the 453 UK servicemen and women who have died in the course of operations in the country as well as to those who had been injured.
The Prime Minister has made an unannounced visit to Afghanistan to meet Ashraf Ghani, the country's new president, and to talk to British troops stationed there.
President Ghani was sworn into office four days ago.
Two Taliban suicide bombers attacked the Afghan capital this morning, killing at least seven people and wounding more than 15, government officials said.
The Taliban, fighting to oust foreign forces and the US-backed government, claimed responsibility for the attacks in the east and west of Kabul.
"Double martyrdom attack has rocked #Kabul city this morning amid current year's ongoing #Khaibar operation," the Taliban said on Twitter, referring to their yearly summer fighting offensive.
Officials from Afghanistan and the United States signed a deal on Tuesday allowing American troops to stay in the country after the end of the year, filling a campaign promise by new President Ashraf Ghani.
There has been an explosion near the airport in Afghanistan's capital as the country's new president was being sworn in, Reuters reported citing a witness.
Local security forces said a suicide bomber attacked a security checkpoint near the airport minutes before Ashraf Ghani was sworn in as president.
It was not immediately clear how many people had been killed and injured in the explosion, the report stated.