KABUL, Afghanistan — The extremist Islamic State group carried out an attack on Tuesday against one of Afghanistan’s most popular Pashto-language TV stations in the heart of the capital Kabul, leaving at least two dead.

A suicide bomber detonated himself at the station gates killing one security guard while one of the three assailants slipped into the compound and killed a female employee. At least 20 others were injured in the attack.

The militants, who wore police uniforms, battled for three hours with security forces, filling the city with the sound of gunfire and explosions and forcing the station to halt its broadcast.

The station was back on the air within hours, however, with one presenter appearing with bandaged hands.

The extremist Islamic State group claimed the assault through their online Amaq News Agency.

It is the latest attack on Kabul, once largely untouched by the violence wracking the rest of the country but now a frequent target. Last month alone, attacks by the Taliban and the Islamic State group claimed 250 lives.

“The majority of our colleagues managed to flee,” station director Abid Ehsas said in an interview with another station. “The number of wounded is high, some were hurt by glass, some threw themselves down off the building.”

He called it an attack on freedom of the press, adding that the station had not received any threats before the attack.

The U.S. Embassy in Kabul condemned the attack, calling it a “terroristic act against free press.”

Various other media outlets have come under attack by militants in recent years in Afghanistan, often amid accusations of broadcasting racy music and other inappropriate content by extremists.

The deadliest happened two years ago when a suicide bomber targeted a bus carrying employees of the popular Tolo TV, killing more than 12 of the staff. The Taliban took responsibility for that attack, which it said was to avenge accusations by the station that it had raped women during its assault in the northern city of Kunduz.

Like most local media, Shamshad also airs anti-Taliban and anti-Islamic State public service announcements.

The attack is part of escalation and expansion of violence in the country this year, 16 years since the U.S.-led troops overthrew the Taliban.

Casualties among civilians and Afghan forces have been soaring from the conflict, with no real victor in sight.

Separately on Tuesday, the U.S. forces in the country announced that its probe found no evidence that civilians had been killed during its airstrikes in northern Kunduz province last week.

Over the weekend, lawmakers from the northern Kunduz region alleged that dozens of civilians, including women and children had died in a joint U.S.-Afghan operation.

“The USFOR-A investigation was conducted independently and concluded that there were no civilian casualties. Specifically, no hospitals or clinics in the local area indicated treatment of people with wounds from armed conflict,” said the U.S. forces statement.

The conflicting reports of civilian deaths also prompted the Afghan government to launch its own investigation.

A spokesman for the Defense Ministry, Dawlat Waziri, earlier said the initial probe by government showed one civilian had been killed and five wounded.

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