Grabove (Ukraine) (AFP) - Russia accused the United States of hindering the OSCE's work in Ukraine, as fighting raged around the crash site of flight MH17 and the Netherlands scrapped plans for an armed international mission to secure the area.
Foreign Minister Sergei Lavrov, in a telephone conversation, asked US Secretary of State John Kerry "to order his subordinates to stop hindering the OSCE from doing its current work", the foreign ministry in Moscow said in a statement Sunday.
Kerry, during the conversation, urged Russia to "begin to contribute to deescalating the conflict", a senior US State Department official said.
Observers from the Organisation for Security and Cooperation in Europe (OSCE) have been unable to access the site where the Malaysia Airlines plane crashed less than two weeks ago, killing 298 people, because of heavy shelling in the area.
Moscow has accused the US of supporting Kiev against the separatist rebels in the restive east of the former Soviet Republic, and of "sharing the responsibility of spilt blood" in the conflict.
The United States and Europe, meanwhile, accuse Moscow of supporting the insurgents, and claim a Russian-made missile was used to shoot down flight MH17.
"Secretary Kerry urged Foreign Minister Lavrov to stop the flow of heavy weapons and rocket and artillery fire from Russia into Ukraine," said the State Department official.
"He did not accept Foreign Minister Lavrov's denial that heavy weapons from Russia were contributing to the conflict."
The two ministers agreed that a ceasefire in east Ukraine was needed, and that negotiations should start under the terms of an agreement signed in April, the Russian ministry said.
According to the State Department official, Kerry underlined Washington's "support for a mutual ceasefire verified by the OSCE and reaffirmed our strong support for the international investigation to show the facts of MH17."
- Armed mission 'not realistic' -
The Netherlands, meanwhile, scrapped plans to send an international armed mission to secure the crash site amid fears of being dragged into the conflict.
Dutch authorities leading the probe into the downing of the jetliner had along with Australia planned to send armed officers, but Prime Minister Mark Rutte said this was no longer viable.
"Getting the military upper hand for an international mission in this area is according to our conclusion not realistic," Rutte told journalists.
Even an unarmed team of Dutch and Australian officers was forced to drop their plans to visit the site Sunday as heavy bombardments rocked towns close to the site, where remains of the victims still lie decomposing under the summer sun.
A small reconnaissance team "stopped out of security concern" after seeing heavy weapons, said Alexander Hug, deputy chief monitor of the OSCE's special mission in Ukraine.
A senior Australian official on Monday said the chances of Dutch and Australian police reaching the crash site were not good, and that the effort could take days.
"If it is a genuine offensive to take back ground we may be some days before we can feel safe and secure to go back in there," Australian Federal Police deputy commissioner Andrew Colvin told Australian media.
So far, investigators have visited the site only sporadically because of security concerns, even though a truce had earlier been called in the immediate area around the site by both Kiev forces and pro-Russian separatists.
Fierce fighting on Sunday claimed 13 lives, including those of two children.
An AFP photographer heard artillery bombardments just a kilometre (half a mile) from the rebel-held town of Grabove, next to the crash site, and saw black smoke billowing into the sky.
Terrified local residents were fleeing and checkpoints controlled by separatist fighters were abandoned.
Ukrainian Foreign Minister Pavlo Klimkin insisted on Twitter Kiev was "committed to its unilateral cease-fire within 40km zone of MH17 site", and "terrorists (are) destroying evidence of the crime".
Amid the fighting, Washington released satellite images to bolster its claim that Russian artillery has fired across the border into Ukraine, targeting government forces in support of separatists.
- Alleged Grad rocket fire -
Fighting was also raging elsewhere as the Ukrainian army pushed on to retake the industrial east.
Ukraine's military accused insurgent fighters of firing unguided Grad rockets at residential blocks in the city of Gorlivka, to the north of Donetsk, "aiming to bring discredit to the Ukrainian army and frighten the non-combatants".
A rebel commander from the self-proclaimed Donetsk People's Republic told a press conference that the situation in Gorlivka was "fine for the moment".
The outskirts of mining hub Donetsk itself were also subject to intense bombardment, some of it apparently Grad rocket fire.
The city of one million has been serving as a base for international monitors and journalists who are travelling regularly to the crash site.
Ukraine's anti-terrorism office said a female Polish journalist working for pro-Kiev Espreso TV was seriously wounded in clashes in the Lugansk region and evacuated.
In Brussels, the European Union is drafting tougher sanctions against Russia -- which it accuses of abetting the insurgency by arming the rebels who allegedly shot down the aircraft.
Sanctions targeting economic sectors including an arms embargo are being considered, while on Tuesday the bloc is expected to unveil more names of individuals and entities sanctioned.
Moscow has blasted the move as "irresponsible", and warned that it jeopardised cooperation on security issues.