Police launched an investigation to ascertain whether the driver's recklessness or a technical fault of the bus caused the crash.

After a passenger bus in Sri Lanka veered off of a cliff and fell into a ravine, 21 people died and 35 others were injured. Sri Lankan authorities are investigating the cause of the accident.

Local television showed the bus lying overturned at the bottom of a precipice while workers and others helped remove injured people from the rubble.