Media playback is unsupported on your device Media caption The BBC's Cindy Sui: "The main wreckage from the airplane has been taken on to a truck"

Rescue teams in Taiwan are continuing to search for the 12 people who remain unaccounted for after a plane crashed in a river.

Thirty-one people are now known to have died when the TransAsia ATR-72 plane came down in Taipei's Keelung River on Wednesday morning.

Fifteen survivors were pulled from the wreckage, including a two-year-old boy.

Taiwan's aviation regulator has ordered all operators of ATR planes to conduct "special checks".

Many of the passengers were Chinese tourists and China will reportedly participate in a probe into the crash.

The death toll was expected to rise as rescue teams searched the river for the missing passengers.

"This morning we have some 60 divers going underwater to search" in addition to 20 boats scouring the river, said Liu Yung-chou, from the national fire agency which is leading the rescue operation.

Aviation authorities in Taiwan said the pilot and co-pilot were among the dead.

The ATR-72 turbo-prop plane had just taken off from Taipei Songshan Airport and was heading to the Kinmen islands, just off the coast of the south-eastern Chinese city of Xiamen.

Dramatic video footage shot from inside a passing car showed the plane banking sharply before clipping a taxi and the edge of the elevated road with its wing.

The final communication from the pilots to air traffic control was "Mayday, mayday, engine flame out", aviation officials confirmed Thursday, after an audio snippet was widely broadcast by local media.

The cause of the crash has not been identified, but the message indicates that one of the engines had stopped working - one propeller appeared from the footage to be not turning.

The aircraft ended up mostly underwater in the river, broken into several pieces. Rescue teams in dinghies ferried survivors to safety, but many of those on board were trapped inside the sunken wreckage.

Image copyright PA

Analysis: Richard Westcott, BBC Transport Correspondent

You would be forgiven for thinking that flying is becoming more lethal. But you would be wrong.

In fact, when you look at the number of crashes and fatalities compared to the huge number of people flying today (3.2 billion passengers last year), we are in a golden era of aircraft safety.

According to safety analysts Ascend, 2014 was narrowly the safest year ever, with one fatal accident per 2.38 million flights, compared to every 1.91 million flights the year before.

Despite the headlines air travel is safer than ever

Overnight, a crane hauled the half-submerged fuselage from the river.

The BBC's Cindy Sui in Taipei says divers are now looking several kilometres downstream of where the plane crashed for wreckage and bodies but visibility underwater is very poor.

There is very little hope any of the 12 missing people will be found alive, she adds.

Image copyright @Missxoxo168 Image caption Dramatic images show the TransAsia passenger plane clipping a bridge as it plunges toward the river

Image copyright EPA Image caption Overnight luggage and personal effects were removed from the plane

Image copyright AFP Image caption Rescue teams were on site rapidly after the plane came down on Wednesday morning

Local media have reported the story of one escape, by a couple and their two-year-old son.

Lin Ming-wei was seated next to where the fuselage broke apart, Taiwan's Central News Agency (CNA) reported. Unhurt, he acted quickly to get out of his seat and help his wife scramble out of the opening.

He found his son in the water and the boy was later resuscitated. Mr Lin's wife and son are recovering in hospital, CNA reported.

Media playback is unsupported on your device Media caption Sudworth: "This is no longer a rescue mission, but a recovery operation"

TransAsia is a Taiwan-based carrier that operates domestically and on some international routes from Taiwan. Its director, Peter Chen, said the aircraft was "the newest model. It hadn't been used for even a year".

The plane's flight data recorders, also known as black boxes, have been recovered.

Taiwan's Civil Aeronautics Administration said in a statement that all 22 ATR planes being operated in Taiwan had to undergo a variety of checks including on the engines, fuel control systems and propeller systems.

ATR is a French-Italian manufacturer. Two French aviation investigators and four from ATR are being sent to help Taiwanese authorities with their probe, reports say.

Last year, a TransAsia plane crashed in Penghu in bad weather, killing 48 people. The carrier was also involved in deadly incidents in 1995 and 2002.