An Afghan soldier screens passengers at a checkpoint on the outskirts of Jalalabad province on June 29, 2015. (Parwiz/Reuters)

A key leader of the Islamic State and another top commander were killed in recent U.S drone strikes in eastern ­Afghanistan, according to intelligence officials here, the latest sign that the radical Islamist group is considered a growing threat in the country.

A strike in Nangahar province — which the U.S. military said occurred Tuesday — killed more than two dozen Islamic State militants, according to local media reports. They included ­Shahidullah Shahid, a former spokesman for the Pakistani Taliban who defected last year to help launch the Islamic State’s branch in Afghanistan. Shahid is thought to have been the group’s chief spokesman in the country.

Afghan intelligence officials said Islamic State commander Gull Zaman also was killed this week in a U.S. drone strike. But it was unclear whether he died in the same strike that targeted Shahid. A U.S. military spokesman in Kabul said several “precision strikes” were conducted against “individuals threatening” U.S. and Afghan forces in two districts of Nangahar on Monday and Tuesday.

As of Thursday night, the Islamic State had not confirmed the reported deaths.

The drone attacks suggest that the United States is becoming increasingly involved in thwarting the rise of the Islamic State — also known as ISIS, ISIL and Daesh — in Afghanistan. Tribal elders and provincial officials in Nangahar said a U.S. air campaign, conducted in conjunction with Afghan security forces­ and intelligence agents, has been underway in the province for two weeks. U.S. drones and fighter jets have been deployed regularly, officials said.

“These assaults have intensified in the past two days,” said Ahmad Zia Abdulzai, a spokesman for the provincial governor’s office. “Some 80, 90 insurgents have been killed in these airstrikes in the past two weeks.”

The strikes come as the Islamic State, which controls swaths of Syria and Iraq, has made steady inroads in Afghanistan this year, although its presence in next-door Pakistan remains limited. In January, the group announced the creation of its Khorasan chapter, a reference to an ancient term for an area that includes Afghanistan and Pakistan.

By February, U.S. military commanders were noticing disaffected Taliban fighters rebranding themselves as Islamic State members. Today, the group is clashing with the Taliban as they jockey for control of territory in eastern Afghanistan. In Nangahar, the Islamic State controls several ­areas.

This week’s assaults also coincided with the launch of peace talks between Afghanistan and the Pakistan-based Taliban leadership. The first session was held Tuesday night near the Pakistani capital, Islamabad. The Islamic State opposes the talks.

For years, Shahid was the chief spokesman for the Pakistani Taliban, frequently appearing in media reports to assert responsibility for some of the grisliest attacks in Pakistan.

But in October, Shahid surprised many analysts when he appeared in a video expressing support for the Islamic State and its supreme commander, Abu Bakr al-Baghdadi. The Pakistani Taliban, which views the Islamic State as a rival and considers Mohammad Omar its supreme leader, quickly severed ties with Shahid. The defector then emerged as a key leader of the Islamic State’s Khorasan chapter.

A spokesman for the U.S.-led coalition in Afghanistan provided no details of the operations or the targets. But Afghanistan’s ­National Directorate of Security said it supplied the intelligence for the strikes, which have unfolded mostly in Nangahar’s Achin and Bati Kot districts, where the Taliban and the Islamic State have waged intense battles.

A powerful tribal elder in Bati Kot suggested that the U.S. strikes may have killed many Taliban fighters, as well.

“Based on the information that I have, American drones have attacked the Taliban and the Daesh fighters while they were fighting each other in Achin district,” said Zahir, the elder, who, like many Afghans, uses one name. “I can say huge numbers of Daesh and Taliban fighters have been killed because both group’s fighters were gathered in one area.”

According to the Long War Journal, a Web site that monitors conflicts, Zaman was the deputy leader of the Islamic State’s Khorasan chapter. Afghan intelligence officials identified Zaman as the group’s “military operations deputy.”

Previously, Zaman had led the Pakistani Taliban’s operations in Pakistan’s Orakzai tribal area, according to the South Asia Terrorism Portal, which monitors violence in the region.

The Pakistani Taliban has been badly weakened over the past year because of defections and an ongoing Pakistani military operation. But one of Pakistan’s most wanted militants, Pakistani Taliban commander Maulana Fazlullah, remains at large.

Fazlullah, the mastermind of a gruesome attack on a school in Peshawar in December, is thought to reside in Afghanistan. Both U.S and Afghan military commanders have said they are searching for him.

sudarsan.raghavan@washpost.com

tim.craig@washpost.com

Craig reported from Islamabad. Mohammad Sharif in Kabul and Haq Nawaz Khan in Peshawar contributed to this report.

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