Pressure is mounting on Russia and Ukraine to give some answers to what caused the crash of a Malaysia Airlines passenger plane carrying 298 people, which U.S. intelligence officials said was caused by a surface-to-air missile.
Amid increasing international calls for an investigation into what brought down flight MH17 over the troubled region of eastern Ukraine, Thursday, U.S. Vice President Joe Biden said the plane crash was "not an accident," adding that it was "blown out of the sky."
Officials on both sides of the crisis in Ukraine have so far blamed each other for the plane crash, with authorities in Kiev releasing what is claimed to be a recording of a Russia-backed rebel admitting to firing the missile that downed the MAS aircraft while Russian President Vladimir Putin said Ukraine must take responsibility for the disaster.
So far, emergency services on the site of the crash in the Donetsk region of Ukaine have uncovered 181 bodies.
In a packed press conference in Kuala Lumpur Friday, Malaysian Transport Minister Liow Tiong Lai said it would be "an outrage against human decency" if the airliner was found to have been shot down.
There were reports Friday that the crashed plane's flight recorders (the so-called black boxes) had been located. Reuters reported that Russian foreign minister Sergey Lavrov saying that Moscow did not plan to take the recorders from pro-Russian separatists in eastern Ukraine, further complicating efforts to find out what happened to flight MH17.
Hillary Clinton, former U.S. secretary of state, told the "Charlie Rose Show" that the "there does seem to be some growing awareness that it probably had to be Russian insurgents."
Clinton added that if there was evidence linking Russia, Europe would have to strengthen considerably their sanctions against Moscow.
Meanwhile in Berlin, German Chancellor Angela Merkel told reporters that Russia must work towards a political solution in Ukraine, and that those responsible for the Malaysian plane being downed must be brought to justice.
Her call to action was joined by U.K. Prime Minister David Cameron who said the "absolutely shocking incident" should not "be allowed to stand."
In a phone call Friday with Dutch Prime Minister Mark Rutte, Putin called for a "thorough and unbiased" investigation into the MAS crash in eastern, the Kremlin told news agencies.
Malaysia Airlines said there were at least 154 Dutch, 27 Australians, 43 Malaysians, including 15 crew and two infants, 12 Indonesians including one infant, nine Britons, four Germans, four Belgians, three Filipinos and one Canadian aboard the Boeing 777 jet.
.There were a further 41 passengers whose nationality was not yet known. MAS said it would release the passenger manifest after notifying next of kin. The Australian newspaper reported that 108 of the passengers were to attend an AIDS conference in Melbourne, Australia.
Malaysia Airlines said Ukrainian aviation authorities told the company they had lost contact with Flight MH17, a Boeing 777 en route from Amsterdam to Kuala Lumpur, about 30 kilometers (20 miles) from Tamak waypoint, which is 50 kilometers (30 miles) from the Russia-Ukraine border.
'A real whodunit'
"This is going to be a real whodunit situation now that everybody is disavowing responsibility," Alan Diehl, a former National Transportation Safety Board investigator, told CNBC.
"The good news is that U.S. may have satellite assets around that border and we may be able to spot where, when and who fired that missile."
UN Chief Ban Ki-Moon urged a "full and transparent international investigation" into the crash. A meeting of U.N. Security Council has been scheduled for Friday morning in New York.
Pro-Russian separatists said they would have up to a three-day ceasefire in Eastern Ukraine to allow for recovery work at the site of the downed airliner, according to a RIA news agency.
The disputed region of eastern Ukraine has seen several clashes over the past week, with exchanges of gunfire between government forces and separatists. On Wednesday evening, a Ukrainian fighter jet was shot down by an air-to-air missile from a Russian plane, Ukrainian authorities said Thursday.
"To bring down an airliner from 33,000 feet you need a good air defense weapon, not just a missile itself and also the radar. That says Russian, and that says to me either a separatist element or the Russians themselves," Retired Col. Ken Allard told CNBC.
Ukraine also has weaponry capable of hitting the passenger plane, Doug Richardson, editor of IHS Jane's Missiles & Rockets, said in a note.
But he noted, "The crew of the Command Post vehicle (containing the data display and control system for the launcher) are likely to have a good idea of the local air activity."
Some noted that the strike may not have been deliberate.
"I just can't imagine the Ukrainian government, Russian government or the rebels wanting to shoot down another country's airliner with all those foreign nationals abroad. I think in all probability, it was accidental,"
While the plane's route was over an area that has seen severe fighting between Ukrainian forces and pro-Russia separatist rebels in recent days, the carrier noted that the flight path had been declared safe and unrestricted by the International Civil Aviation Organisation. The International Air Transportation Association also noted the airspace wasn't subject to restrictions, MAS said.
A great deal of passenger airline traffic usually travels through the area on a daily basis, but many international carriers have now announced they will be changing their routes. Two other flights -- one from Singapore Airlines and one from Air India -- may have been within 30 kilometers of MH17 at the time it disappeared from radar, according to data from FlightRadar24, a website providing maps of real-time air traffic.
Calling the downed plane a "terrible tragedy," Obama said the U.S. will offer any help it can to determine what happened and why.
Malaysian Prime Minister Najib Razak said he was shocked by the reports and was also planning an investigation.
In the markets, Malaysian Airline System shares fell as much as 17.8 percent before retracing some losses to trade around 20.5 sen, off around 8.9 percent in intraday trade.
—CNBC.com with wires