INTERNATIONAL experts have started recovery work at the wreckage site of a downed Malaysian airliner in east Ukraine despite clashes nearby between government forces and pro-Russian rebels.

The group was the largest to reach the site since flight MH17 was shot down over rebel-held territory on July 17, killing 298 people.

Roads had for days been too dangerous to use because of heavy fighting, frustrating efforts to recover all the victims' remains and start a thorough investigation.

In the latest clashes, the rebels killed at least 10 Ukrainian paratroopers in an ambush near Shakhtarsk, one of the closest towns to the wreckage site.

The rebels said they had pushed back government forces around Shakhtarsk, where fighting has raged for several days. A Ukrainian military official said a further 13 troops were wounded and 11 were unaccounted for.

The recovery mission included 70 experts from Australia and the Netherlands, whose countries suffered a big loss of life in the shoot-down, as well as representatives of the Organisation for Security and Cooperation in Europe (OSCE).

An advance team drove to the site from Donetsk on Thursday but only stayed for about an hour after the sides halted fighting along the route.

Agreement was later reached to extend the limited ceasefire around the route, making it a safe corridor, at talks in Belarus involving Russia, Ukraine, the rebels and the OSCE.

Kiev has accused the rebels of planting mines in the region near the site, suggesting they want to hamper the investigation and hide evidence but an OSCE official said no evidence had been found to back up the allegations.

Ukrainian officials say about 80 bodies have not been recovered from the wreckage of the Boeing 777. The 298 victims included 193 Dutch and 27 Australians, as well as 43 Malaysians.

The US says separatists probably shot down the plane with a Russian-made missile but the rebels and Moscow deny that claim.