Seoul, Nov 27 (TIWN) South Korea's military guided back a North Korean merchant vessel, after the ship crossed the inter-Korean maritime border southward due to an engine problem, the Joint Chiefs of Staff (JCS) of South Korea said on Wednesday.

South Korea's military says it believes the North Korean ship crossed the sea boundary on Wednesday due to bad weather and an engine problem.

It says it's the second time that South Korea has fired warning shots to drive back a North Korean ship in the area since South Korea's current liberal government took office in 2017. The first incident happened in September.

Ties between the two Koreas are strained amid a stalemate in U.S.-led diplomacy on ending the North Korean nuclear crisis.

North Korea said Monday its troops conducted artillery firing drills near the sea boundary, drawing formal protests from South Korea.