Three NATO soldiers were killed early Sunday morning in a suicide attack for which the Taliban has claimed responsibility.

The attack occurred during a routine security patrol on foot outside a large U.S. air base in Afghanistan.

All three fatalities were from the Czech Republic, a member nation of both NATO and the international security force known as Resolute Support, said Lt. Gen. Ales Opata, chief of general staff of the Czech army.

One American service member and two Afghan soldiers were wounded in the blast.

“Their sacrifice will endure in both our hearts and history, and further strengthen our resolve.” — U.S. Army Gen. John Nicholson, Resolute Support and U.S. Forces-Afghanistan commander

The attack took place in Charikar District, Parwan province, about 40 miles north of Kabul, near Bagram Air Base, said Wahida Shahkar, a spokeswoman for the provincial governor in the Parwan province.

“My thoughts and prayers, along with those of all of the 41-contributing Resolute Support nations, are with the families and friends of our fallen and wounded service members, and our injured Afghan brothers and their families,” said U.S. Army Gen. John Nicholson, Resolute Support and U.S. Forces-Afghanistan commander. “Their sacrifice will endure in both our hearts and history, and further strengthen our resolve.”

The U.S. military said it would not release more details until the families of the fallen service members have been notified.

NATO formally concluded its combat mission in Afghanistan in 2014, but thousands of forces are still providing support and training to Afghan troops, while carrying out counterterrorism missions.

Sunday's attack was similar to one that occurred near Bagram in December 2015, when six U.S. troops were killed by a suicide bomber riding a motorcycle. Three others were injured in that attack.

The Associated Press contributed to this report.