KABUL (Reuters) - The police chief of Afghanistan's capital quit on Sunday, his spokesman said, following a third deadly Taliban attack in 10 days on foreign guest houses in Kabul.

Also on Sunday, the charity whose guest house was targeted in the latest attack said three of its aid workers were killed by insurgents who used guns and explosives. Earlier, Kabul police said one foreigner and other Afghan died.

The statement on the website of the U.S.-based Partnership in Academics and Development (PAD) did not give the nationalities of the three. A Western security official said they were South Africans.

Meanwhile, 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.

The Taliban and its militant allies have increased pressure on Kabul, which has seen a spike in deadly attacks on military and civilian targets.

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.

The Taliban said on Saturday it had attacked the foreign guesthouse because it was a center of Christian faith. This was the second time this year the Taliban targeted a group that it said had links to Christianity.

PAD, which supports education in Afghanistan, said it would continue its activities despite the attack.

The group could not be reached immediately for comment.

(Additional reporting by Mirwais Harooni; Editing by Richard Borsuk)