A man armed with a Molotov cocktail is being blamed for starting a fire on a South Korean subway train that left at least 100 people dead and more than 130 injured.
The man is being questioned, but his motive is still a mystery.
Police in the city of Daegu say that subway passengers struggled with a man who was trying to ignite what appeared to be a milk carton containing flammable liquid. They say that during the struggle, the man dropped the lighter he was carrying, causing the container to explode and setting a subway car ablaze as it moved between two stations.
One woman says she told subway workers about the fire but they didn't know where the flames were coming from or what to do. She says they should have been more responsive.
Police say a male suspect has been arrested and is being interrogated. There was no concrete indication of what the motivation for the attack might have been, but several media reports say the suspect apparently has a history of mental troubles.
The incident took place just before 1000 local time, as the morning commuter rush was winding down in Daegu, which is 200 kilometers southeast of the capital Seoul. Much of the city's downtown was paralyzed by the chaos.
South Korean television showed choking black smoke rising from subway ventilation shafts and enveloping the center of the country's third largest city. It took firefighters three hours to put out the blaze.
Rescuers wearing oxygen tanks could be seen bringing dozens of people to the surface on stretchers, their faces and clothes black with soot. The victims, some in serious condition, were being treated at eight nearby hospitals.
Toxic smoke hampered efforts to rescue 14 subway employees trapped on a station platform, and official say all of those were later found dead. Poisonous fumes also caused shopkeepers in nearby areas to flee. Several trains were believed to be stuck in the tunnels, and rescuers were reported to be combing the tracks.
The incident came amid increased tensions on the Korean Peninsula. South's communist neighbor, North Korea, has been making increasingly warlike statements in recent days. But it appears there was no connection between the North Korean moves and the subway attack.