Ukraine fighting reaches Donestk: Kiev urges rebels to let civilians flee

Fighting in eastern Ukraine reached the rebel stronghold of Donetsk on Tuesday as separatists and government troops exchanged rocket fire in neighborhoods on the edge of the city.

The spread of fighting into the city itself marks a decisive turn for the conflict. Ukraine's military has urged pro-Russia separatists to allow civilians to flee cities in the country's besieged east as fears of a humanitarian crisis continue to grow.

The army has been advancing on the main rebel-held city of Donetsk since the end of a cease-fire at the start of July.

"Yesterday [Monday], forces from the Ukrainian anti-terrorist operation occupied the city of Yasinuvata, 12 miles north of Donetsk, which is an important railway hub," Ukrainian security spokesman Andriy Lysenko told journalists.

"The seizure of the town allowed for the encirclement of Donetsk from the north and the closing down of an important channel for the supply of weapons and technology to the terrorists."

More than three months of civil war have already claimed more than 1,150 lives, and since the Ukrainian military advance, the civilian death toll in the conflict has passed 800, with thousands more wounded.

Human Rights Watch (HRW) said Tuesday that pro-Kremlin rebels were hindering the treatment of civilian casualties by threatening doctors, hijacking ambulances and stealing medical equipment.

"Pro-Russian insurgents' attacks on medical units and personnel are putting sick and vulnerable people and those who care for them at risk," Yulia Gorbunova, Europe and Central Asia researcher at HRW, said in a statement.

"This appalling disregard of people who are sick or wounded can be deadly and needs to stop immediately."

An earlier HRW report criticized the use of unguided rockets on both sides, especially in heavily populated areas.

"The use of indiscriminate rockets in populated areas violates international humanitarian law, or the laws of war, and may amount to war crimes," the report said.

"If insurgent and Ukrainian government forces are serious about limiting harm to civilians, they should both immediately stop using these weapons in populated areas," said Ole Solvang, senior emergencies researcher for the group.

The army denies responsibility for civilian deaths.

The onslaught against separatist fighters has focused recently on besieging the main rebel strongholds of Donetsk and Luhansk, as well as the smaller but strategically important town of Horlivka.

The wild card is whether Russia, which has been building up troops along the nearby border, will come to the rebels' rescue. President Vladimir Putin has faced increasing pressure from Russian nationalists urging him to send in the army to back the insurgency.

Ukrainian spokesman Lysenko said Tuesday that 45,000 Russian troops equipped with 160 tanks, more than 1,300 armored vehicles, 192 military airplanes and 134 attack helicopters are at the moment stationed along the border. NATO's current estimate is that there about 20,000 Russian troops massed just east of Ukraine's border.

Russia escalated its troop presence along the Ukrainian border earlier this year, but then pulled back large numbers of soldiers in May.

Both the United States and Ukraine say Russia has again built up its military presence since then. Moscow denies that claim.

Fighting across eastern Ukraine has forced more than 285,000 people to flee their homes, according to U.N. figures released Tuesday. The U.N. refugee agency said more than 117,000 have left for other places inside Ukraine, while another 168,000 people have crossed into Russia.

Pro-Russian separatists in eastern Ukraine have been battling the Kiev government since April. Ukraine and Western countries have accused Moscow of fueling the mutiny with weapons and soldiers, a claim the Russian government has repeatedly denied.

The West has also accused Russia of most likely providing the insurgents with surface-to-air missiles that may have been used to shoot down a Malaysia Airlines passenger jet over rebel-held territory on July 17, killing all 298 people on board.

Kiev on Monday also reported it was negotiating for the return of some 300 troops who they say were forced to retreat into Russia after hours of missile and mortar bombardment from across the border.

Russia's security service said border guards had allowed the Ukrainians to cross after they agreed to give up their weapons.

The military advances against pro-Moscow separatists came as more remains from the downed MH17 plane were flown to the Netherlands for identification, and Malaysian experts joined the Dutch and Australian probe at the site of the July 17 crash.

Al Jazeera and wire services