The government says it has yet to confirm any casualties among South Koreans after two high-speed trains collided in southern Spain, killing at least 39 people and injuring dozens of others.

An official at Seoul’s foreign ministry said Monday that the South Korean diplomatic mission continues to check for news of any South Korean casualties.

Foreign media outlets reported that carriages from a Madrid-bound train derailed and crashed into an oncoming train in Adamuz, near the city of Córdoba, around 7:40 p.m. Sunday local time.

An investigation was launched to determine the cause, and the Spanish transport minister told local reporters that railway experts who were consulted were “extremely baffled” by the accident.

Spain’s worst-ever high-speed train derailment took place in the country’s northwestern Galicia region in 2013, when 80 people were killed and 140 others injured.