SEOUL, South Korea — North Korea fired several ballistic missiles into the sea on Monday, South Korea’s military said, hours after South Korean and U.S. troops kicked off their large annual combined drills, which the North views as an invasion rehearsal.

At least 15 people were injured after South Korean fighter jets involved in a live-fire drill dropped bombs on Pocheon, Seoul's military said.

A blast took place in Pocheon after two South Korean fighter jets mistakenly dropped eight air-to-surface bombs on the civilian town Thursday.

The incident took place at 10:04 am (local time), and the Air Force assured that it was investigating the accident. The authorities also apologised for the damage caused to the civilians

The South Korean military said the accident near the North Korean border occurred during training ahead of Freedom Shield, an annual U.S.-South Korea joint military exercise.

South Korea's military says North Korea has fired several ballistic missiles into the sea. The launch Monday happened hours after South Korean and U.S. troops kicked off their large annual combined drills,

Dozens of activists and residents from Pocheon in South Korea, staged a demonstration on Friday (March 7) and demanded a halt to military drills a day after fighter jets accidentally dropped bombs on a civilian area,

As a result of the mistaken bombing of a village in South Korea by fighter jets during military exercises, 29 people were injured, including 15 civilians. A tragic incident occurred during joint military maneuvers between the US and South Korea.