Twenty-eight of the 96 people aboard the internal UNI Airlines flight from Taipei to Hualien were injured. At least two people are in critical condition with severe burns.

The BBC's Simon Mercep reports: "In all, 28 people required medical treatment"

Following an initial investigation, Transport Minister Lin Feng-cheng said there apparently was some type of an explosion in the plane. Authorities have yet to determine what caused it.

Pilots, controllers, witnesses and maintenance technicians are being questioned to establish the exact cause.

Witnesses reported a ball of fire on the runway after the jet landed at Hualien Airport, 180km (108 miles) south-east of Taipei, following a 25-minute flight from the capital.

Officials from the Cabinet-level Aviation Safety Council (ASC) ruled out mechanical failure or pilot error as factors behind the accident.

"Judging from a large hole on the fuselage of the MD-90 plane, and the way in which the steel skin of the fuselage around the hole had burst outward, an explosive was deemed to be to have been the most likely cause of the damage," an agency official is quoted as saying.

'Strange noise'

As the plane touched down, a loud "strange noise" came from the cabin and thick smoke poured from an overhead luggage compartment, said UNI vice chairman Si Chung-ching.

Ball of fire after landing

Eighteen passengers were taken to hospital, three of them for emergency treatment. Two people suffered burns covering more than 60% of their bodies, Mr Si said.

"There was an explosion above us, and many people had burns on their faces or holes in their clothes," a passenger told a local cable station.

Hualien Airport was closed after the accident which happened at around 12.40 local time.

TV footage showed black smoke belching from the plane's fuselage as firefighters doused the flames.