KABUL, Afghanistan >> Two U.S. soldiers were killed and six wounded in a so-called insider attack in eastern Afghanistan’s Nangarhar province late Saturday when an Afghan dressed in an Afghan army uniform opened fire, the U.S. military said.

A member of the Nangarhar Provincial Council, Ajmal Omer, told The Associated Press the gunman was killed. There have been numerous attacks by Afghan national army soldiers on their allied partners over the 18 years of Afghanistan’s protracted war.

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

In a statement, the U.S. military said “an individual in an Afghan uniform opened fire on the combined U.S. and Afghan force with a machine gun. We are still collecting information and the cause or motive behind the attack is unknown at this time.”

Omer, who is a member of the provincial council, is from Nangarhar province’s Sherzad district, where he said the incident took place. An Afghan soldier was wounded, Omer said.

The U.S. military said American and Afghan military personnel were fired on while conducting an operation in Afghanistan’s eastern Nangarhar province.

Last July, two U.S. service members were killed by an Afghan soldier in the southern Kandahar province. The shooter was wounded and arrested. In September, three U.S. military personnel were wounded when an member of the Afghan Civil Order Police fired on a military convoy, also in Kandahar.

The incident came as Washington has sought to find an end to the war in Afghanistan.

Washington’s peace envoy Zalmay Khalilzad has been meeting with Taliban representatives in the Middle Eastern state of Qatar in recent weeks. He’s seeking an agreement to reduce hostilities to get a peace deal signed that would start negotiations among Afghans on both sides of the conflict.

In his State of the Union Address on Tuesday, President Donald Trump referenced the peace talks, saying U.S. soldiers were not meant to serve as “law enforcement agencies” for other nations.

“In Afghanistan, the determination and valor of our war fighters has allowed us to make tremendous progress, and peace talks are now underway, ” he said.