Updated 18.42
A passenger plane that crashed as it flew over eastern Ukraine with 295 people on board was reportedly shot down.
The Malaysia Airlines plane, which was flying from Amsterdam to Kuala Lumpur, was travelling at an altitude of 33,000 feet when it was shot down, Russia's Interfax news agency reported.
An adviser to the Ukrainian interior ministry told the news agency the Boeing 777 was brought down by a Buk ground-to-air missile.
All 280 passengers and 15 crew members who were on the plane are believed to have died, he added.
In a statement, the carrier said "Malaysia Airlines confirms it received notification from Ukrainian ATC that it had lost contact with flight MH17 at 1415 (GMT) at 30km from Tamak waypoint, approximately 50km from the Russia-Ukraine border".
"Flight MH17 operated on a Boeing 777 departed Amsterdam at 12.15pm (Amsterdam local time) and was estimated to arrive at Kuala Lumpur International Airport at 6.10 am (Malaysia local time) the next day".
"The flight was carrying 280 passengers and 15 crew onboard".
A number of videos apparently filmed near the village of Grabovo, Donetsk, where the plane came down, showed plumes of thick, black smoke rising high into the air.
The flight was a codeshare operated in conjunction with KLM - flight number KLM 4103.
TV channel Russia 24 broadcast similar pictures, while a Reuters correspondent at the scene said he could see the wreckage of a burning aircraft and bodies on the ground.
The plane, which one eyewitness said split in two on impact, is almost unrecognisable in pictures of the crash site, which showed debris scattered across a vast area.
Alexander Borodai, the eastern Ukraine separatist leader, said the aircraft was shot down by Ukrainian government forces - a claim backed by a separatist from Krasnyi Luch, who told Reuters the rebels did not have weapons capable of shooting down a plane at such height.
However, officials in Kiev denied any involvement, with Ukrainian Prime Minister Arseniy Yatsenyuk ordering an immediate investigation into what he described as a "catastrophe".
The Department of Foreign Affairs has said there is "no indication" of any Irish passengers onboard the flight at this stage.
An image reportedly showing the remains of the plane
The Kremlin said Russian President Vladimir Putin had offered "his sincerest words of sympathy and support to families and friends of the victims", while Malaysian Prime Minister Najib Razak said he was "shocked" by the tragedy.
Meanwhile airplane maker Boeing has said "Our thoughts and prayers are with those on board MH17, as well as their families and loved ones. We stand ready to provide assistance".
Reporter Katie Stallard, in Moscow, said media reports suggest the plane came down in an area where there has been recent heavy fighting amid continuing tensions between Russia and Ukraine.
Data from Flightradar24 indicates the plane had just passed the city of Kremenchuk, around 186 miles from the Russian border, when it disappeared.
Data suggests it came down near the city of Kremenchuk
Relatives of the victims of the MH370 tragedy also released a statement, saying "Who would do such poisonous thing to a civil aeroplane?".
"Passengers on board are ordinary people, just like our relatives. Why let them experience the torture? Why let other people feel the same pain as we do?" they added.
