Some NATO troops suffered light injuries Monday when a helicopter made a “hard landing” in Afghanistan’s southeastern Paktia province, NATO officials said.

NATO said an investigation had been launched to determine what triggered the emergency landing — just two days after insurgents shot down a different coalition helicopter, killing 30 U.S. troops and eight Afghans.

“Initial reporting indicates there was no enemy activity in the area at the time of the incident,” the coalition said in a statement about Monday’s incident, which happened in the Zormat district, a restive, rugged region of Afghanistan.

NATO declined to provide details about the type of helicopter or its mission.

A spokesman for the coalition said the landing site has been secured. He refused to give information about whether the incident happened during an assault on insurgents, as reported by some provincial officials.

U.S. military officials said the helicopter was a Chinook, which is usually used to ferry troops and equipment. Only the crew was aboard.

The shooting down of the helicopter Saturday in Maidan Wardak province was the deadliest single incident for American forces in the nearly decade-long conflict in Afghanistan.

A day after that incident, a NATO helicopter made a hard landing in Khost province, near Paktia, NATO said. There were no casualties.

There has been a rise in crashes of NATO and U.S. military aircraft in recent months, many of them in the eastern region, where foreign troops have shifted part of their focus after making strides against pockets of militants in the south.

Salahuddin is a special correspondent.