Two U.S. troops were killed and six were wounded in an apparent insider attack in Afghanistan according to military officials.

The soldiers were involved in a firefight on Feb. 8 in Sherzad district, Nangarhar province. The wounded service members are receiving medical treatment at a U.S. facility.

Afghanistan’s defense ministry said one Afghan soldier was also killed and three injured in the assault.

“Upon completing a key-leader engagement at the district center, current reports indicate an individual in an Afghan uniform opened fire on the combined U.S. and Afghan force with a machine gun,” Army Col. Sonny Leggett, spokesman for U.S. Forces-Afghanistan, said in an emailed statement.

“We are still collecting information and the cause or motive behind the attack is unknown at this time. The incident is under investigation,” he said.

The Associated Press reported that a member of Nagarhar’s provincial council said that the gunman was killed, but neither the U.S. military nor the Afghan defense ministry has confirmed to the AP the attacker’s fate.

Earlier this evening, notifications began going out to the families of members of the 7th Special Forces group killed and wounded in an Afghanistan firefight, the group posted on its Facebook page Saturday night.

“Several 7th Special Forces Group (Airborne) Soldiers were injured or killed during combat operations in Afghanistan on February 8, 2020. The 7th Special Forces Group Headquarters is poised to support the Service Members and their families during this difficult time,” said Col. John W. Sannes, 7th Special Forces Group Commander.

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“The families of the deceased and wounded are being notified. In accordance with DoD policy, the names of the casualties are being withheld until 24 hours after their next of kin notification is complete.”

Officials from Army Special Force Command sent out a media release echoing the comments on the Facebook page, but did not elaborate.

An Afghan defense ministry official, who was not identified because he was not authorized to speak to the media, told the Associated Press that the shooter was an Afghan soldier who had argued with the U.S. forces before opening fire. The official said the shooter was not a Taliban infiltrator, according to AP.

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Officials from U.S. Forces-Afghanistan — the headquarters overseeing the U.S. mission in Afghanistan — earlier said that the U.S. and Afghan forces conducting an operation in Nangarhar province were engaged by direct fire on Saturday, according Leggett.

One official told Agence France-Press that the attack happened in the Shirzad district military headquarters and that foreign forces had cordoned off the area.

“Several helicopters landed in and departed from the HQ compound taking out casualties. We don’t know how many killed or wounded," the official told AFP.

For years Nangarhar province has been a haven for the Islamic State group’s faction in Afghanistan. The Taliban also operates in the area.

President Donald Trump reiterated Tuesday in the annual State of the Union speech his desire to bring troops home from Afghanistan and end the wars in the Middle East.

“In Afghanistan, the determination and valor of our warfighters has allowed us to make tremendous progress, and peace talks are underway,” he said. “I am not looking to kill hundreds of thousands of people in Afghanistan, many of them innocent. It is also not our function to serve other nations as a law enforcement agency.”

There are roughly 13,000 U.S. troops in Afghanistan. Defense Secretary Mark Esper has said the Pentagon may reduce the American footprint in the country to 8,600 with or without a deal with the Taliban.

Peace talks with the Taliban are ongoing, but definitions over reduced violence and a cease-fire continue to bog down the talks. Secretary of State Mike Pompeo said he wants “demonstrable evidence” that the Taliban can carry through on their promise to reduce violence in the country, according to the Associated Press.

Reporter Kyle Rempfer contributed to this story. The Associated Press also contributed to this report.

This is a developing story. Please stay with Military Times for updates.