Image copyright AP Image caption Checks have been ordered on all ATR planes in active service in Taiwan

Taiwanese airline TransAsia Airways says it is cancelling 90 flights so that its pilots can attend training, after one of its planes crashed on Wednesday.

Flight GE235 plunged into a river in the capital Taipei, killing at least 40 of the 58 people on board.

Officials are probing why both plane engines were off during the crash.

Data suggests that the pilots, who are among the dead, may have shut one engine off after the other lost power.

Taiwan's Civil Aeronautics Administration (CAA) has ordered retraining for all TransAsia pilots flying its ATR fleet.

"All 71 ATR pilots will take part in proficiency tests carried out by the CAA and third-party professionals for an estimated four days," TransAsia Airways said in a statement (in Chinese).

The aviation regulator has also ordered engine and fuel system checks on the remaining 22 ATR-manufactured planes currently in active service on the island.

More bodies found

Five more bodies were retrieved from the Keelung River on Saturday, bringing the total toll to 40, the Taipei fire department said.

The bodies were found downriver from the crash site.

Divers and rescuers are scouring the river for three more people who remain missing. Fifteen others were rescued alive from the plane on Wednesday.

Image copyright AP Image caption Rescuers found five more bodies on Saturday, but three people remain missing

Thomas Wang, executive director of Taiwan's Aviation Safety Council, said on Friday that the plane's right engine triggered an alarm just 37 seconds after taking off from the Taipei's Songshan airport.

The main pilot could be heard on cockpit voice recordings saying the engine had experienced a "flame-out", Mr Wang said, which can occur when the fuel supply to the engine is interrupted.

Media playback is unsupported on your device Media caption The BBC's Cindy Sui says accident investigators will soon determine whether or not the deadly crash was mechanical or human error.

However, he said data showed that the engine had in fact been moved into idle mode.

Seconds later, the pilots shut down the left engine, meaning neither engine was producing any power. A restart was attempted, but the plane crashed 72 seconds later.

Officials said it was unclear why the left engine had been turned off, especially as the plane, an ATR 72-600, is able to fly with just one functioning engine.

Mr Wang said it was too early to draw firm conclusions about why the first engine had lost power but he told the BBC that the pilots had not followed normal procedure.

Officials have praised the chief pilot, Liao Chien-tsung, who is believed to have deliberately steered the plane away from blocks of flats and commercial buildings before the crash.