Investigators probing the downing of Malaysia Airlines flight MH17 in eastern Ukraine said Tuesday they had found fragments "probably" from a Russian-made surface-to-air missile at the crash site.

The passenger jet was shot down over Ukraine on July 17 last year, during heavy fighting between government forces and pro-Russian separatists. All 298 people onboard were killed.

Ukraine and many in the West have accused the rebels of blowing the Boeing 777 out of the sky, saying they may have used a BUK missile supplied by Russia.

Moscow and the rebels deny any responsibility and point the finger at Ukraine's military.

Around two thirds of the victims were Dutch citizens on their way from Amsterdam to Kuala Lumpur, many of them children starting their summer holidays.

Dutch public prosecutor Fred Westerbeke said that international and Dutch investigators were examining seven "considerable fragments of some size... probably from a BUK missile system."

A joint statement from prosecutors and the Dutch Safety Board (OVV) said the fragments were "secured during a previous recovery mission (at the crash site) in eastern Ukraine and are in possession of the criminal investigation team and the Dutch Safety Board."

But investigators said it was not yet clear whether the apparent missile pieces were related to the attack.

"It's too early to say that the fragments we found were, for instance, from the BUK rocket that possibly shot down MH17," Westerbeke told state broadcaster NOS.

But the investigation was "really getting closer" to finding out who was behind the attack, he said.

The downing of MH17 pushed relations between Russia and the West -- which were already at their lowest point since the Cold War -- into even deeper confrontation over the conflict in east Ukraine, which has claimed more than 6,800 lives in 15 months.

A shaky ceasefire has been in place since February, but the EU warned Tuesday that escalating attacks in government-held areas violated the peace deal brokered by Europe.

- 'Realistic scenario' -

The statement from the OVV and the Joint Investigation Team (JIT) said the fragments "can possibly provide more information about who was involved in the crash of MH17."

The JIT, which is carrying out the criminal probe, has representatives from the Netherlands, Ukraine, Australia, Malaysia and Belgium -- the countries worst affected by the crash.

"The JIT will internationally enlist the help of experts, among others forensic specialists and weapon experts," it said.

Dennis Schouten, deputy head of the association of MH17 victims' relatives, told AFP that the announcement was "in line with expectations."

"This was already one of the most realistic scenarios," he said.

Dutch authorities completed recovery of debris and bodies from the crash site in April this year, having previously been hindered by ongoing fighting.

All but two of the dead have so far been identified using DNA samples, dental records and personal effects.

- Soil samples -

In June, Dutch experts returned to eastern Ukraine and took soil samples from a field from where the suspected BUK missile may have been fired.

Both the Russian and Ukrainian militaries have BUK missiles in their arsenal, and the system's Russian manufacturer said in June that based on publicly available photographs of the wreckage the plane was likely shot down by one of its projectiles.

International air investigators, comprising representatives from the Netherlands, Ukraine, Malaysia, Australia, Britain, the United States and Russia, are currently meeting in The Hague to discuss a draft report from the Dutch Safety Board into what caused the crash.

Russia last month vetoed a bid at the United Nations Security Council to set up an international tribunal to try those behind the downing of the aircraft.

Countries involved in that bid are now looking at other means to carry out a prosecution, although no suspects have yet been publicly identified.

The OVV is to release its final report into what, but not who, downed the aircraft in October.

Air investigators are also probing the decision-making process that allowed civilian airliners to fly over a warzone where several Ukrainian military aircraft had previously been shot down by separatists at high altitude.

cjo/kjl/cb

Malaysia Airlines

Team