VILNIUS, Lithuania (AP) — Powerful explosions were heard in the suburbs of Lithuania's capital Wednesday morning after several rail cars loaded with liquefied natural gas caught fire, police said.

One person was injured, according to the fire and rescue department. Columns of smoke were visible across Vilnius and residents in the area were warned to stay indoors.

Interior Minister Vladislavas Kondratovičius told reporters initial information suggests that “the fire was most likely caused by a violation of occupational safety conditions, but all versions are being investigated.”

The carriages that caught fire belong to Polish company Orlen, police said.