SEOUL — Twenty-one U.S. servicemembers were injured when a U.S. military helicopter made a “hard landing” Tuesday near the Demilitarized Zone during exercises with South Korea.

Fifteen were treated at the Yongsan Garrison hospital in Seoul and released. The other six were still there late Tuesday afternoon in stable condition, officials said.

The CH-53E Super Stallion helicopter was conducting routine flight operations in support of exercise Ssang Yong — a Korean Marine Exchange Program linked to the ongoing Foal Eagle exercise — with a crew of five from the 31st Marine Expeditionary Unit stationed in Okinawa, Japan, when it went down hard near the Jipo-ri Range near the border-area town of Cheolwon around 1 p.m., a U.S. Forces Korea statement said.

“The CH-53E has an excellent operational safety record,” the statement said. “A comprehensive investigation will take place to determine the facts and circumstances surrounding this incident.”

A Cheolwon firefighter said initial indications suggested the helicopter was battered by a gust of wind as it was landing.

The joint Foal Eagle exercises, the largest of the year, have been going on for weeks and are scheduled to run through April 30. They have been the subject of almost-daily condemnation in recent weeks from North Korea, which claims they are practice for a pre-emptive attack on the rogue nation.

USFK officials insist the exercises are defensive in nature.

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