KABUL, Afghanistan -— A car bomb exploded outside a police station in the Afghan capital on Wednesday, killing at least 10 people and wounding nearly 100, officials and a security source said, heightening security concerns ahead of planned elections next month.

Taliban insurgents claimed responsibility for the strike, which came a day after the militants and U.S. diplomats spoke of making progress in peace talks in Qatar.

The powerful blast occurred in the southwestern part of Kabul but was felt across the city. It shattered windows in houses, shops and offices, and sent a thick plume of smoke into the air.

Mohammad Jawad, who lives nearby, said seven members of his family were wounded by flying glass at his house.

"I was having breakfast when I felt a strong wave, then came the boom," he said.

Fawad, a 24-year-old barber who was close to the attack site, said he couldn't feel anything for 15 seconds after the "very loud boom" went off. "I thought I was dead," he said.

A security source said at least 10 police and possibly a similar number of civilians were killed in the attack. A spokesman for the Public Health Ministry, Wahiddullah Mayar, released only the number of wounded, saying that 95 people were hurt, including women and children.

The attack further raises questions about the state of security in Afghanistan's capital, which has been the focus of campaigning for presidential elections slated for Sept. 28.

On Tuesday, the Taliban warned they intend to derail the campaign process and the election, which has been delayed twice already. The insurgents urged voters to stay away from election-related events to avoid harm.

Last month, presidential running mate Amrullah Saleh had a narrow escape when a suicide bomber and gunmen attacked his office, killing about 20 people.