Fighting in Ukraine's east blocks access to Flight MH17 wreckage

Ukrainian armed forces on Sunday mounted a major onslaught against pro-Russian separatist fighters in the country's east in an attempt to gain control over the area where Malaysia Airlines Flight 17 was shot down earlier this month.

At least 13 people in Horlivka were killed in clashes between Ukrainian troops and the rebels, according to the Donetsk regional government, which is loyal to Kiev but is based elsewhere since the rebels took over. Horlivka lies 20 miles north of the main rebel-held city of Donetsk.

Ukraine's National Security Council spokesman Andrei Lysenko said that Ukrainian troops were engaging rebels at several other locations, including near the town of Debaltseve, which is 15 miles northwest of the crash site.

Russian state news agency RIA Novosti reported Sunday that a column of Ukrainian armored personnel carriers, trucks and tanks had entered the town of Shakhtarsk, 10 miles west of the site of the crash. Shakhtarsk is a strategic town in the area. By controlling the town, the Ukrainian army would be cutting off the regional capital, Donetsk, from the highway leading to the Russian border.

Earlier Sunday, a team of international monitors said they had abandoned plans to visit the crash site due to fears it was not safe, even though Malaysia had said that rebels agreed to allow access.

Alexander Hug, the deputy head of a monitoring team from the Organization for Security and Cooperation in Europe, said it was too dangerous for the unarmed officers to travel to the site from its current location in Donetsk.

The U.S. State Department, meanwhile, released satellite images that it says back up its claims that rockets have been fired from Russia into eastern Ukraine and heavy artillery for separatists has also crossed the border.

A four-page document released by the State Department seems to show blast marks from where rockets were launched and craters where they landed. Officials said the images, sourced from the U.S. Director of National Intelligence, show heavy weapons fired between July 21 and July 26 — after the July 17 downing of Malaysia Airlines Flight 17, which killed all 298 people on board.

Russia dismissed U.S. allegations it was about to hand over more missiles to the separatists, who Western leaders say almost certainly shot the airliner down by mistake with a Russian-supplied surface-to-air missile.

The separatists deny any involvement and Moscow says it has not supplied them, suggesting Ukrainian forces were to blame.

"Kiev is trying to destroy the evidence of a crime by its army," separatist leader Aleksander Borodai said Sunday, referring to the Ukrainian army offensive some distance from the site.

Malaysian Airlines Flight 17 was shot down over a part of eastern Ukraine controlled by pro-Russian separatists.

Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry agreed in a phone conversation on Sunday on the importance of ensuring a swift cease-fire in eastern Ukraine, according to a statement from Moscow.

But the State Department said Kerry did not accept Lavrov's denial that heavy weapons from Russia were contributing to the conflict and urged him "to stop the flow of heavy weapons and rocket and artillery fire from Russia into Ukraine, and to begin to contribute to deescalating the conflict."

The Russian statement described the crisis in Ukraine as an "internal conflict."

Washington and the West accuse Moscow of supporting rebels fighting Ukrainian troops in the east of the former Soviet republic. Moscow denies involvement. 

Hug said the police mission, comprised of officers from the Netherlands and Australia, will reconsider resuming operations if security improves. Malaysian experts are also due to join them next week.

"We continue to reassess the situation continuously and we will start to redeploy tomorrow morning back to the site if the situation changes," Hug said.

Australian Prime Minister Tony Abbott said earlier Sunday that unarmed Australian police would be part of the Dutch-led police force to secure the area and help recover victims' remains.

Abbott said that by using unarmed police, Ukraine's Parliament will not need to ratify the deployment as it would if the security force were to be armed.

"This is a risky mission. There's no doubt about that," Abbott told reporters. "But all the professional advice that I have is that the safest way to conduct it is unarmed, as part of a police-led humanitarian mission," he said.

Malaysian Prime Minister Najib Razak said in a statement that his country would send dozens of police and that his country had received assurances from pro-Russia separatists that they would provide protection for investigators.

Ten days after the MH17 disaster, a full-fledged investigation still has not begun at the site, compromising evidence and leaving some bodies still unrecovered. Concerns about the integrity of the site were raised further when a couple that had flown from their home in Perth, Australia, visited the wreckage-strewn fields Saturday outside the village of Hrabove and even sat on part of plane's wreckage.

Flights from Ukraine to the Netherlands have taken 227 coffins containing victims of the plane disaster. Officials say the exact number of people held in the coffins still needs to be determined by forensic experts in the Netherlands.

The Malaysia Airlines disaster prompted some expectations in the West that Russia would scale back its involvement in the uprising in Ukraine's east, but the opposite seems to be the case.

In Warsaw, Poland, about 250 people marched through the city to protest what they called the "terror" imposed by Russian President Vladimir Putin in Ukraine. Some of the demonstrators carried Ukrainian flags, and there were banners that proclaimed "Putin is a Sponsor of Terror" and "Europe, Stop Just Talking. Start Taking Action! Stop Terror in Ukraine."

Wire services