A wounded man is carried to a hospital after a blast in Kabul on Wednesday. (Mohammad Ismail/Reuters)

A car bomb exploded Wednesday outside a police recruitment center in the Afghan capital, killing 14 people and wounding nearly 150, officials said, heightening security concerns ahead of elections planned for next month.

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

The blast followed a violent night in Kabul, where security forces conducted operations against hideouts of Islamic State affiliates in three parts of the capital, the government said.

Explosions and protracted gunfire could be heard for several hours. A group of militants and members of the security forces were killed, Afghanistan’s intelligence agency said Wednesday.

The Wednesday attack occurred in a densely populated area in the southwestern part of the city. The police recruitment center previously has come under attack.

The blast was felt across Kabul. It shattered windows in houses, shops and offices and sent a thick plume of smoke into the sky.

Mohammed Jawad, who lives near the site of the attack, 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 could not feel anything for 15 seconds after the “very loud boom” went off. “I thought I was dead,” he said.

Khoshal Sadat, a senior deputy interior minister, said at a news conference that 14 people were killed and 145 were wounded, including 92 civilians.

He said the Taliban has stepped up its attacks in cities and other civilian population areas lately as part of a move to “provoke the public against the system” after having suffered setbacks in intense offensives by government forces nationwide in recent months.

Wahidullah Mayar, a spokesman for the Public Health Ministry, said women and children were among the wounded.

Several videos circulating on social media showed extensive damage to the recruitment center, with piles of rubble and corrugated metal scattered in a vast yard.

The attack intensifies concerns about the state of security in Afghanistan’s capital, which has been the focus of campaigning for the presidential election, slated for Sept. 28.

On Tuesday, the Taliban warned that it intends to derail the campaign process and the election, which have 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.

The United Nations on Wednesday denounced the Taliban’s threat to disrupt the election, warning that attacks on polling centers and voters “are clear violations of international law, and perpetrators of such crimes must be held accountable.”

“All citizens — whether voters, candidates or election-related staff — have the right to be free from fear, intimidation and violence at all stages of an elections process,” the U.N. Assistance Mission in Afghanistan said in a statement. It called on the Taliban to respect civilians who “engage in their constitutional right to participate in elections.”

While condemning Wednesday’s attack, President Ashraf Ghani said the Taliban has stepped up raids to extract concessions in the negotiations. His government, which has come under criticism for failing to stop the mounting violence, has been barred from the talks because the Taliban objects to its participation.

“By repeating such tragedies and humanitarian crimes, not only will they not gain any concession during the peace talks, but they will be severely suppressed in all corners of the country by our valorous defense and security forces,” Ghani said in a statement.

Sediq Seddiqi, a spokesman for Ghani, said increased attacks by the Taliban showed that the group was “the main hurdle for peace” in Afghanistan.

Pamela Constable in Islamabad, Pakistan, contributed to this report.