A North Korean soldier was shot by fellow guards as he defected to South Korea Monday, according to South Korean officials. He was the seventh soldier to defect since 2012 and the third defector this year.

The soldier was shot as he made his way across the heavily guarded border between the two countries called the demilitarized zone (DMZ). The border is approximately two and a half miles wide and is littered with minefields and fenced off with high guard posts and sentries.

The North Korean was posted near the Joint Security Area, a part of the DMZ where both sides can meet to talk, according to CNN. The soldier was found about around 150 feet south of the border with wounds to his elbow and shoulder and was evacuated to a hospital, according to the New York Times.

Before this year there were two soldier defections in 2012, one in 2015 and one in 2016.

The defector is currently in South Korean military custody.

“Our military has raised the alert level in anticipation of North Korean provocation. The military is maintaining a full readiness,” said South Korea’s Joint Chiefs of Staff in a statement.

The defection came amid a giant joint naval exercise between the U.S., South Korea and Japan. The U.S. sent three aircraft carriers to Southeast Asia, marking the first time three carriers have sailed together in over a decade. The show of force followed President Donald Trump and North Korea trading barbs while the president was on a 12-day tour of Asia. North Korean state media called Trump a “dotard” which is an insulting term for an elderly person, typically a senile one. Trump called North Korea’s leader Kim Jong Un “short and fat.”

Coincidentally, a U.S. man was arrested in South Korea for trying to cross the DMZ into North Korea around the same time as the soldier defected. The man, a 58-year-old from Louisiana, was reported by locals and arrested by South Korean intelligence services. His motive for attempting to cross one of the world’s most dangerous borders is unclear.