A member of Afghanistan’s National Defense and Security Forces (ANDSF) turned his gun on his allies on Monday, killing a U.S.-NATO coalition service member from the Czech Republic and wounding two others in the second insider attack in less than a week.

The U.S.-NATO mission, dubbed Resolute Support (RS), announced on Tuesday, “A Resolute Support service member was killed in Herat province today. Two other Resolute Support service members were wounded in the incident. Initial reports indicate the attack was committed by a member of the Afghan security forces.”

The deceased and injured service members are from the Czech Republic, the country’s ministry of defense confirmed, noting that the incident took place in Shindand district of Herat province, Khaama Press (KP) reported.

According to the Czech ministry, the injuries are not life-threatening.

In a statement, the Taliban acknowledged the incident in Herat province, but it did not explicitly take credit for the attack.

“According to a recent report, an infiltrator Mujahid – Wahidullah – hailing from Nangarhar province, opened fire on American troops inside Shindand airbase afternoon hours today, leaving several invaders killed and wounded,” the terrorist group reported.

Monday’s attack came after a Taliban-linked provincial governor’s bodyguard opened fire on a high-profile security meeting in a heavily fortified government compound in Kandahar, killing three people and wounding 13 others, including three Americans — a U.S. general, a coalition contractor, and a civilian.

The Taliban claimed responsibility for the attack, claiming that the targets were U.S. Gen. Scott Miller, the top commander of American and NATO forces, and Gen. Abdul Raziq, the police chief of Kandahar known as the Taliban’s “torturer-in-chief.”

Gen. Miller survived the attack, but Raziq did not.

The U.S. Special Inspector General for Afghanistan Reconstruction (SIGAR), an American watchdog agency, believes the threat from insider attacks has intensified since the United States transitioned security responsibilities to the ANDSF and declared its combat mission over at the end of 2014.

“Since responsibility for security began transitioning to the Afghan government in 2014, ‘green-on-green’ insider attacks in which ANDSF personnel are attacked from within their own ranks, often by an insurgent infiltrator, have consistently been a severe problem,” SIGAR noted in its most recent report to Congress.

There were 33 “green-on-green” attacks as of mid-May, marking an increase of seven from the same period last year.

The ANDSF, which includes military and police units, incurred 132 casualties (95 killed and 37 wounded) as a result the insider attacks between January and mid-May.

This year, there have been a few “green-on-blue” insider attacks in which ANDSF personnel turned their weapon on U.S.-NATO coalition troops.

In July, a “green-on-blue” attack killed one American service member and killed two others.

A couple of months later, in September, an insider attack killed one U.S. service member and wounded another.

That means “green-on-blue” attacks this year have killed at least three U.S.-NATO coalition troops and wounded six others.

According to SIGAR, there were no “green-on-blue” attacks this year before mid-May.