Kabul, Afghanistan -- A powerful bomb blast rocked the Afghan capital early Monday, sending smoke billowing from downtown Kabul and leaving more than 100 people wounded. The Taliban claimed responsibility for the attack as peace talks between senior members of the Islamic extremist group and U.S. negotiators appeared to struggle to make headway in Qatar.

The bomb blast hit a military compound in Kabul less than two miles from the U.S. Embassy. Health Ministry official Wahid Mayer said 116 people were wounded, including 26 children and six women. He confirmed at least one person was killed by the blast, but added that the toll could still rise.

The explosion went off with Kabul's streets packed with morning commuters. Mohammad Karim, a police official in the area, said a car bomb exploded outside a Defense Ministry building. Militants then ran into a nearby high-rise in a crowded market area and began firing down toward the ministry. Police and Afghan security forces swarmed the area and cordoned it off.

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CBS News' Ahmad Mukhtar said at least two assailants took up positions in nearby buildings and engaged Afghan forces on the ground. Later the Ministry of Interior said the attack was over and the situation was under control.

An injured Afghan man is brought on a stretcher to an Italian aid organization's hospital after a car bomb attack in Kabul, July 1, 2019. Getty

The capital had been relatively quiet in recent months following a spate of violent explosions, many claimed by the local Islamic State of Iraq and Syria (ISIS) affiliate.

Peace prospects dim

The attack in Kabul came as the latest round of talks between the United States and the Taliban moved into a third day in the Middle Eastern state of Qatar, where the militant group maintains a political office. Some sources told CBS News that the talks -- the seventh round of direct negotiations between the parties -- appeared unlikely to progress beyond Monday, however.

The Taliban said their focus during the talks was on getting an announcement of a timetable for the withdrawal of U.S. and NATO troops from Afghanistan. That announcement would, theoretically, be accompanied by a Taliban promise to hold intra-Afghan talks and agree to an eventual cease-fire.

Suhail Shaheen, spokesman for the Taliban's political office in Doha, told The Associated Press on Monday that "our main concern is to make sure a timeline for troop pullout is announced." Taliban officials have previously said they want all foreign troops withdrawn within six months.

Washington has pushed for a longer timeline of a year to 18 months, however, and the firm insistence that the Taliban open a direct dialogue with the Afghan government. The militants have thus far refused to talk to the Afghan government, calling it a U.S. puppet regime.

Washington accelerated attempts to find a negotiated end to America's longest war with the appointment last September of Afghan-born American Zalmay Khalilzad, who was a special presidential representative to Afghanistan and later U.S. ambassador in Kabul in the years immediately following the ouster of the Taliban.

U.S. and European officials with direct knowledge of the talks told CBS News' Sami Yousafzai on Monday that Khalilzad planned to leave this round of negotiations and return to Washington as the Taliban had not shown enough flexibility in their demands. Officials on both sides of the discussion had called this round crucial -- possibly a last chance to strike a peace deal.

Khalilzad's staff did not confirm his plans, however, and it appeared that his negotiating team, at least, would remain in Doha to keep working with the Taliban representatives. In past rounds of the talks, the senior envoy has left Doha for consultations while his team continued working.

But Shaheen, the Taliban spokesman, hinted in a tweet on Monday at an impasse.

"When the withdrawal timetable of foreign forces is announced in the presence of international representatives then we will start negotiations with Afghan side, but we will not talk with the Kabul administration as a government," he said.

CBS News' Ahmad notes that Khalilzad has repeatedly stated that "nothing will be agreed until everything is agreed" -- which includes direct talks between the Taliban and Afghan President Ashraf Ghani's government.

Secretary of State Mike Pompeo, center left, walks with Afghan President Ashraf Ghani's Chief of Staff Abdul Salam Rahimi, as he arrives at the Presidential Palace in Kabul, Afghanistan, June 25, 2019, during an unannounced visit. Getty

Less than a week ago, U.S. Secretary of State Mike Pompeo paid a short visit to Kabul and said the Trump administration was hopeful that a peace deal with the Taliban was achievable by September. A day after he left, two U.S. troops were killed by small-arms fire in Afghanistan.

More than 2,400 U.S. service personnel have died in Afghanistan since the U.S.-led coalition invaded in October 2001 to oust the Taliban and hunt down al Qaeda chief Osama bin Laden following the Sept. 11, 2001, attacks on the United States.

A senior official with the Afghan government, which has deeply resented being sidelined in the peace talks, told CBS News the attack in Kabul on Monday was evidence that the U.S.-Taliban negotiations were not making progress, and were unlikely to bring peace to his country.