Afghan security forces inspect the site of the car bomb attack in Ghazni province on Sunday. (Rahmatullah Nikzad/AP)

For the second time in a week, Taliban insurgents Sunday greeted the opening of new peace discussions in Qatar with a deadly suicide bombing at home, this time killing 12 people and wounding at least 179 in an attack in conflicted Ghazni province. 

The defiant message from the morning attack on a national intelligence compound, which wounded scores of children at a nearby school, drew a sharp contrast with optimistic statements by U.S. officials and negotiators, who expressed hope this week that a peace agreement — or at least the outlines of one — could be reached by Sept. 1.

 Just as a delegation of Afghan leaders were finishing breakfast and heading to an ice-breaking “peace summit” with Taliban officials in Doha, the Qatari capital, word came that the insurgents had claimed responsibility for a rush-hour assault in Ghazni city, the provincial capital they besieged and shut down last August.

A spokesman for the Taliban, Zabiullah Mujahid, quickly claimed responsibility for Sunday’s attack and said “dozens” of intelligence employees had been killed. Intelligence officials said two of its employees were dead and 80 others wounded. The Ghazni governor’s office said in a Facebook post that 12 people had been killed and 179 wounded, many of them schoolchildren.

The bombing came one day after the top U.S. negotiator, Zalmay Khalilzad, told journalists that the new round of negotiations that began Thursday in Doha, where the Taliban’s political office is located, had been “the most productive” session since such talks began in September.

Khalilzad said “substantive progress” had been made on all four major issues: a timetable for withdrawing U.S. and NATO forces, a Taliban guarantee to prevent international terrorist groups from operating in Afghanistan, a permanent cease-fire, and direct negotiations with Afghan officials. He said he hoped the sides could settle on a road map for peace before Afghan presidential elections in late September.

But some observers said the attack cast new doubt on the Taliban’s commitment to settling the 18-year conflict, and that hopes of reaching even a framework agreement by early September were unrealistic.

The attack came as 50 Afghan leaders from across the country, as well as a few government officials acting in a “personal” capacity, prepared to spend two days talking informally with the Taliban and “getting to know each other,” as Khalilzad said Saturday, at a meeting sponsored by Germany.

The U.S.-Taliban talks have been put on hold for the next several days to allow those discussions to advance. U.S. and Afghan officials hope they will pave the way for formal talks between the Taliban and the Afghan government.

The insurgents have refused to recognize or meet with Afghan officials, claiming they are U.S. puppets.

Michael Kugelman, an analyst at the Woodrow Wilson International Center for Scholars in Washington, said the informal discussions still leave Afghan officials “sidelined” from the peace process because the Taliban have insisted they can participate only as private citizens.

Other analysts have warned that if the United States agrees to withdraw its forces too hastily, the Taliban would have no incentive to negotiate in good faith with Afghan leaders. Others say that trying to hold presidential elections amid a drawn-out peace process could damage both efforts.

 Laurel Miller, a former U.S. special representative for Afghanistan, said seeking a peace deal before elections could “add a new element of chaos.” A peace deal with the United States, she said, “does not address the really hard questions of what role and how much power the Taliban will have.”

Sediq Seddiqi, the spokesman for Afghan President Ashraf Ghani, said Sunday that “it is beyond understanding that a group like the Taliban, while their leaders are sitting in Qatar talking about peace, commits this horrific and deplorable crime that took many innocent lives.” 

Save the Children, an international charity active in Afghanistan, said many of the injured children were hospitalized with severe shrapnel injuries to the head and chest. The group said Sunday’s blast showed the “devastating consequences of using explosive weapons in populated areas,” and urged “all armed groups” to “stop killing and maiming innocent children.”

Ghazni province has been attacked multiple times by the Taliban in the past year, including the August assault that left scores dead and whole city blocks in ruins. The insurgents control several rural districts and have attacked others, causing thousands of residents to flee. Voting in parliamentary elections in October was canceled across the province. 

In recent months, Afghan security forces have pushed back aggressively with airstrikes and ground attacks in the embattled province, taking back several key districts and vowing to restore order and peace.

Last month, Afghan army officials flew a group of journalists to one rural district that had been recaptured.

Nasir Ahmad Faqiri, president of the Ghazni Provincial Council, said Sunday that the Taliban attack was intended to “hide their recent failures as they have come under pressure from Afghan air and ground attacks.” 

He said the Taliban “want to show the international community and the Afghans in Qatar that they can carry out attacks even in the cities. Naturally such attacks will have a negative effect on talks.”