By Kay Johnson and Jessica Donati
KABUL (Reuters) - The Kabul police chief resigned on Sunday after Taliban gunmen killed three members of a South African family in the capital, while officials said Afghan forces had ousted insurgents trying to seize former U.S. and British base Camp Bastion in the south.
Taliban fighters breached the perimeter of Camp Bastion in the southern Afghan province of Helmand three days ago, just one month after the base was handed over to the Afghan army.
The latest Taliban attacks have dented confidence in the country's security force and added to concern the police and army will struggle to hold strategic territory after most foreign troops pull out at the end of 2014.
The guest house attacked by the Taliban in Kabul on Saturday, the third attack on a foreign guest house in 10 days, was home to staff of the U.S.-based charity Partnership in Academics and Development (PAD).
PAD said on its website that three people were killed by insurgents who used guns and explosives. They were identified as members of the same South African family - a father and his two teenage children - by a colleague of the mother, who was not in the compound at the time.
The family had lived in Afghanistan for nearly 12 years, with the father running the charity and the mother working as a doctor at a Kabul clinic, the colleague said.
The Taliban said on Saturday they had attacked the foreign guesthouse because they believed it to be a Christian center. This was the second time this year the Taliban targeted a group that it said had links to Christianity.
The 17-year-old son had been applying to universities in the United States, while his sister was 14, according to their mother's colleague, who asked not to be identified for security reasons.
Kabul's police spokesman declined to comment on the reason for the chief's resignation.
"We can only confirm... he will not continue his job as police chief anymore," Hashmat Stanekzai said.
PAD, which supports education in Afghanistan, could not be reached immediately for comment.
Violence across Afghanistan has surged this year as the Taliban and their allies have stepped up their activities ahead of the scheduled withdrawal of most international troops by the end of next month.
Over the past 10 days, three compounds used by foreign organizations have been hit by armed attackers. In separate attacks in Kabul, two American soldiers, two British embassy workers and dozens of Afghan civilians have died.
In Helmand province, Afghan soldiers ousted a group of Taliban from Camp Bastion after a third day of fighting. At least five soldiers were killed in the battle that started late on Thursday.
By Sunday, troops were clearing the part of the sprawling base that had been seized by a few dozen insurgents, according to the governor's spokesman, Omar Zwak.
Violence in another part of Helmand added to the weekend toll, Zwak said, with 12 soldiers dying in Sangin district after their smaller outpost was attacked.
(This story has been refiled to fix layout of third paragraph, no change to text)
(Additional reporting by Mirwais Harooni; Editing by Richard Borsuk and Raissa Kasolowsky)