KABUL—A blast that killed scores of students preparing here for their university entrance examinations capped an extraordinary week of violence in Afghanistan, undermining what the U.S. and Afghan governments had considered real prospects for an imminent cease-fire and a new round of peace talks with the Taliban.
Afghanistan’s Health Ministry said at least 48 people were killed and another 67 wounded in the capital on Wednesday when a man wearing an explosives vest blew himself up in a classroom full of students. The blast left the floor strewn with twisted metal, broken desks and human limbs.
Suspicion for carrying out the bombing fell immediately on the extremist Sunni Muslims of Islamic State, whose local affiliate has been behind a spate of attacks in mainly Shiite neighborhoods of western Kabul, where Wednesday’s blast occurred.
The Taliban, the country’s largest insurgency, denied responsibility for the Kabul suicide attack, but it came on the back of an unusually deadly series of actions the militants have undertaken since Friday, when they launched a predawn attack on the strategic eastern city of Ghazni, about a two-hour drive from Kabul.
Since then, government soldiers and police have been enmeshed in a protracted battle that has underscored the Taliban’s resiliency and the shortcomings besetting Afghanistan’s security forces.
The U.S. has made training and equipping those forces the primary focus of its strategy to prevent Afghanistan from again becoming a launching zone for international terrorism. To that end, the U.S. has spent at least $78 billion there following the September 11, 2001, attacks on the U.S. homeland.
Local officials and residents of Ghazni accused the government and military of ignoring their warnings of an impending Taliban attack, responding too slowly once it started and failing to coordinate the movements of army and police units. Defense Minister Tariq Shah Bahrami said Monday that the country’s young army and police may have made mistakes.
On Wednesday, President Ashraf Ghani of Afghanistan said military operations to root out remaining Taliban were continuing in one neighborhood of the city, which lies on one of the country’s principal roads. The U.S. military, which was advising its Afghan partners, described the heavily damaged city as quiet after carrying out airstrikes in support of Afghan ground forces, using among other aircraft a B-1 heavy bomber from the U.S. air base in the Gulf state of Qatar.
But the ebbing of violence in Ghazni this week hasn’t ended the troubles of government forces. Late Tuesday, Taliban fighters attacked a police garrison on the outskirts of the northern city of Baghlan, triggering hours of fighting that left 37 officers dead. The militants also seized caches of weapons and at least four armored vehicles, according to Mahbubullah Ghafari, a councilman from Baghlan province.
The Afghan army bars soldiers from serving in their home provinces, but most of dead police were locals, adding to the grief. “It was a horrible and barbaric attack,” Mr. Ghafari said. “It’s broken our hearts.”
Tuesday’s Baghlan province attack was the second major Taliban assault on a defense base in less than two days. At least 43 government soldiers were killed when Taliban fighters overran an army base in northwestern Faryab province on Monday, after a two-day siege during which the troops requested but didn’t receive reinforcements, local officials said. Forty soldiers surrendered to the insurgents.
With the Taliban striking deadly blows to government forces across the country, expectations faded that either side would declare cease-fires to coincide with next week’s Muslim festival of Eid al-Adha. Last week, government officials and Taliban leaders had separately been discussing the logistics for such a truce, following a similar one in June. Preparations were also quietly under way for a second round of talks next month between U.S. officials and Taliban representatives, a senior Afghan official said, following a meeting in Qatar last month.
The unilateral cease-fires observed by both sides during the June holiday triggered an outpouring of good will that stunned Afghans and foreign capitals alike. Rival combatants were seen embracing each other, dancing arm-in-arm and taking selfies.
In a bid to build on that unexpected success, U.S. officials met Taliban representatives in Qatar last month to discuss how to revive a peace process aimed at reaching a negotiated settlement of the 17-year war. The meeting amounted to the first such high-level, direct talks between the two sides in at least 2½ years.
A second successful truce, which had been expected next week, was seen as building momentum toward another meeting between U.S. diplomats and Taliban representatives next month, a senior Afghan official said.
It isn’t clear that the recent violence will scotch those plans. Top Taliban leaders were expected to meet this week to discuss a cease-fire, a person knowledgeable about their activities and thinking said. As for the government, “We haven’t made a decision yet,” a senior Afghan official said late Wednesday.
The person familiar with the Taliban said the spate of high-profile attacks was aimed at gaining more diplomatic leverage with the U.S. as a peace process advances.
“Without progress on a peace agreement between the Taliban and the Americans, the attacks will continue, even increase,” the person said.
The surge in attacks is also intended, he said, at demonstrating that efforts by the Afghan government and the U.S. to discredit the insurgency on theological grounds haven’t undermined the morale of the insurgency’s rank-and-file.
In recent months, the powerful Muslim nations of Saudi Arabia and Indonesia, backed by the Afghan government and its main ally, the U.S., have hosted large gatherings of Muslim religious scholars and clerics. Each has culminated in communiqués declaring the Taliban’s continued fighting un-Islamic and urging a peaceful settlement of the war.
On Aug. 6, the insurgency countered with a gathering of its own in the Pakistani city of Quetta that drew some 4,000 sympathetic religious scholars and clerics, the person said. The assembly backed the Taliban’s claim that its fight against the Afghan government and foreign military forces is a holy war. It urged Taliban leaders against negotiating with the Kabul government, which it considers a U.S. puppet.
In Baghlan on Wednesday, residents mourning the dead indicated that the reservoir of goodwill generated by June’s outpouring was gone.
Fueled by the events in Ghazni, rumors of a possible Taliban strike had swirled in Baghlan in recent days, said Mr. Ghafari, the provincial councilman.
“Students, shopkeepers, everyone started making preparations for a possible raid,” Mr. Ghafari said, even though there were no specific signs that an assault on the police post was imminent.
Now, few in Baghlan were awaiting word of a cease-fire next week, Mr. Ghafari said.
“Our people are thirsty of peace. That’s why we welcomed the Taliban and gave them flowers in June,” he said. “Now they’ve killed police and soldiers, the true defenders of our land. I doubt the people of Baghlan will welcome any kind of truce now.”
Write to Craig Nelson at craig.nelson@wsj.com
Corrections & Amplifications Next week’s Muslim holiday in Afghanistan is Eid al-Adha. An earlier version of this article incorrectly gave its name as Eid al-Fitr, which is another holiday that fell in June. The article also incorrectly said that previous holiday had occurred in July. (Aug. 15, 2018)