A plane which crashed in eastern Ukraine with 298 people, including nine Britons, on board was reportedly shot down as it flew near airspace deemed unsafe for passenger jets.

Malaysia Airlines flight MH17, which was heading from Amsterdam to Kuala Lumpur, was travelling at an altitude of 33,000 feet (10,000 metres) when contact was lost.

An adviser to the Ukrainian interior ministry told the Interfax news agency the Boeing 777 was brought down by a Buk ground-to-air missile , killing all 283 passengers and 15 crew members.

As well as the Britons, the victims included 154 Dutch, 45 Malaysians, 27 Australians, 12 Indonesians, four Germans, four Belgians, three Filipinos and one Canadian.

Three infants are among the dead, and the nationalities of 41 passengers have yet to be verified. These are thought to include a number of Americans .

Some of the passengers were on their way to a UN Aids conference in Melbourne, the Australian government has said.

Plumes of thick, black smoke could be seen rising high into the air near the village of Grabovo, Donetsk, where the airliner came down.

The plane, which one eyewitness said split in half on impact, is almost unrecognisable in pictures of the crash site, with burning wreckage scattered across a vast area .

US President Barack Obama has told the Netherlands Prime Minister that Washington would support a "prompt, full, credible and unimpeded international investigation" into the disaster.

Malaysia Airlines, still reeling from the loss of flight MH370 in March, has said all its European flights will be taking alternative routes with immediate effect.

It revealed the route taken by flight MH17 had been declared safe by the International Civil Aviation Organisation.

The Interfax news agency has reported that the plane's 'black box' flight recorder has been recovered.

Officials in Kiev were quick to deny any involvement, with President Petro Poroshenko lamenting what he called an "act of terrorism".

US Vice-President Joe Biden said the jet appeared to have been deliberately "blown out of the sky", with an unnamed US official blaming Ukrainian separatists backed by Russia in an interview with the Reuters news agency.

However, separatist leader Alexander Borodai said the aircraft was shot down by Ukrainian government forces - a claim backed by another separatist, who told Reuters the rebels do not have weapons capable of shooting down a plane at such height.

Sky's Katie Stallard, in Moscow, said Igor Strelkov, the commander of the pro-Russian Donetsk People's Republic, appeared to have boasted about the incident on social media.

In one deleted message recovered by Sky News, he allegedly wrote: "We warned you not to fly over our sky."

Ukraine's security service also released what it claimed was a recording of an intercepted phone call between two Russian military intelligence officers, discussing the downing of the plane.

Sky's Mark White, citing aviation sources, said the aircraft appeared to have been flying close to a block of airspace deemed "unsuitable for civilian aircraft".

Air traffic controllers confirmed the plane was flying in open airspace but just 1,000 feet (300 metres) above a restricted zone.

"It raises questions about why the plane was near an area it had been advised not to fly through," White said.

"Did it stray into that area by accident or did the pilot decide it was a risk worth taking, perhaps as a fuel saving measure?"

Stallard said the plane came down in an area that had seen heavy fighting in recent days, as tensions between Russia and Ukraine continue.

Data from Flightradar24 indicates the plane, which took off from Schiphol airport at 12.15pm local time, had just passed the city of Kremenchuk, around 300km (186 miles) from the Russian border, when it disappeared.

Russian President Vladimir Putin said the incident was "absolutely unacceptable" and an "awful tragedy", but added: "This would not have happened if there were peace on this land ... and, certainly, the state over whose territory this occurred bears responsibility."

Meanwhile, relatives of the victims of the MH370 tragedy have released a statement, saying: "Who would do such a 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?"

The disaster is the latest in a line of reported attacks on planes in Ukrainian airspace and comes a day after one of the country's Sukhoi-25 fighter jets was shot down .

:: Malaysia Airlines has set up an emergency line, 00 6 037 884 1234, for people worried their relatives may be on the flight.