SEOUL (Kyodo) -- A man started a fire inside a moving subway train in Seoul around 8:40 a.m. on Saturday, forcing about 400 passengers to evacuate on foot through the tunnel, according to South Korean media.

The incident occurred near the center of the capital. The suspect fled the scene but was apprehended at a nearby station. Police are investigating his motives, as he appears to have started the fire using gasoline he brought with him.

Around 20 people were taken to hospital with smoke inhalation and other injuries, most of them believed to be minor. Service on the line where the fire broke out was suspended for about an hour.

A male passenger was quoted by media as saying that smoke filled the carriage and some people were screaming in shock.