A tour bus carrying visitors from China burst into flames on a highway near Taiwan's capital on Tuesday, burning to death all 26 people on board, officials said, in the deadliest incident involving Chinese tourists to the island.

The accident took place on the No. 2 national highway in Taoyuan county, south of Taipei, where the island's international airport is located, the county's fire and rescue service said in a statement.

It said 24 of those on board were visitors from northeast China's Liaoning province who had been scheduled to fly home on Tuesday afternoon. The others killed were the driver and a tour guide, both Taiwanese.

Taoyuan fire chief Lai Chi-chong said all of the victims died inside the bus. "There was not enough time for them to escape," he told reporters.

Doors impossible to open

Video from the scene showed both of the bus's doors were pressed up against the highway's guard rail, making them impossible to open.

Many of the bodies were badly charred, some of them piled in front of the unopened emergency exit, Taiwan's official Central News Agency and other media reported.

A bus burst into flames in Taiwan early Tuesday, killing all 26 people on board. (Google/CBC)

There was no official word on the cause of the fire, although CNA and others reported that the bus apparently burst into flames after spinning out of control and smashing into the highway's guard rail.

CNA cited eyewitnesses as saying the bus had been giving off smoke and swerving from lane to lane prior to crashing and bursting into flames.

The drivers of other vehicles pulled over and attempted to put out the flames with fire extinguishers, but the fire had grown too large for them to put out, CNA said.

Photos from the scene showed flames and thick black smoke pouring from the front of the bus shortly after the crash.

The accident was the deadliest involving Chinese visitors to Taiwan since the island opened up to Chinese tourism in 2008, according to Taiwanese government records and reports of previous incidents.

Since then, 83 Chinese have died while on trips to Taiwan, including Tuesday's victims, and another 100 have been injured. Several of those deaths involved bus crashes, and the latest accident is likely to revive safety concerns surrounding the treatment of Chinese tourists, most of whom come on cheap group tours.

Tuesday's was the deadliest incident involving Chinese tourists in Taiwan since 19 were killed in a tour bus crash in 2010.