From NPR - News National/International -

Malaysian Jet That Crashed In Ukraine May Have Been Shot Down

Ukrainian workers are seen at site of crash site

Ukrainian emergency workers are seen at what's reported to be the crash site of a Malaysia Airlines Boeing 777 in the settlement of Grabovo in the Donetsk region Thursday. Flight MH17 had 295 people aboard when it took off in Amsterdam on Thursday. (Maxim Zmeyev/Reuters/Landov)

A Malaysia Airlines Boeing 777 with 295 passengers and crew aboard has crashed in eastern Ukraine in an area of the country that has been wracked by a separatist insurgency.

Ukrainian President Petro Poroshenko said he would "not exclude that this plane was shot down, and we stress that the armed forces of Ukraine did not take action against any airborne targets," he said. "We are sure that those who are guilty in this tragedy will be held responsible."

Later, Poroshenko called the crash an act of terrorism, according to The Associated Press.

Malaysia Airlines flight #MH17 just before it disappeared over Ukraine. pic.twitter.com/xvDHsEQtkg

— Flightradar24 (@flightradar24) July 17, 2014

The head of Ukraine's emergency agency was quoted by Reuters as saying "armed terrorists" were hampering efforts to reach the crash site. However, the AP, citing Russian sources, says separatists planned to call a three-day cease-fire to allow crash investigators access to the area.

A separatist leader based in Donetsk, Ukraine, where the plane reportedly went down, said his fighters took no action, telling Interfax that they don't have weapons that could reach that altitude. Ukraine reported earlier Thursday that two of its aircraft had been shot down in recent days.

A U.S. official tells NPR that the airliner was likely shot down by a surface-to-air missile. A congressional staffer says that U.S. surveillance assets covering the area should be able to determine a likely cause of the crash and that lawmakers expect to get a report within 24 hours.

Malaysia Airlines acknowledged Thursday that it lost contact with the passenger jet over Ukraine, issuing the following statement:

"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.

Data on the FlightAware website suggest MH17, a daily flight, normally travels at an altitude of around 33,000 feet, or some 6 miles in the air. A video posted to YouTube showed a smoldering area on the ground that is said to be the crash site.

"I am shocked by reports that an MH plane crashed. We are launching an immediate investigation," said Malaysian Prime Minister Mohd Najib Tun Razak, in a tweet.

Russian President Vladmir Putin discussed the plane crash with President Obama during a telephone conversation between the two leaders, the White House confirmed.

Later, Obama said the "world is watching" reports of the downed jetliner.

"It looks like it might be a terrible tragedy," he said, adding that his team is trying to determine whether there were any Americans aboard the plane. "That is our first priority."

"The United States will offer any assistance we can to help determine what happened, and why," he said.

The U.S. Federal Aviation Administration also warned airlines last month about flying over parts of Ukraine owing to the ongoing conflict, but the warning did not specifically cover Donetsk, where the plane went down, nor did the International Civil Aviation Organization, or ICAO, warn of that region.

Boeing issued a statement saying, "Our thoughts and prayers are with those on board the Malaysia Airlines airplane lost over Ukrainian airspace, as well as their families and loved ones. Boeing stands ready to provide whatever assistance is requested by authorities."