Ukrainian officials said their forces advanced to the outskirts of a key town north of Donetsk on Saturday as they try to retake the stronghold held for months by rebels.

The move comes as Ukrainian forces appear to have gained some momentum recently by retaking control of territory from the rebels. But Russia also appears to be becoming more involved in the fighting, with the US and Ukraine accusing Moscow of moving heavily artillery across the border to the rebels.

Ukrainian national security spokesman Andriy Lysenko said Ukrainian forces were outside Horlikva, just north of the regional center of Donetsk.

Once they can take Horlivka, "the direct route is open for the forces of the anti-terrorist operation to the capital of the Donbass region - the city of Donetsk," Lysenko said. "The approaches to Donetsk are being blocked so that the terrorists do not get the chance to receive ammunition, reinforcements or equipment."

Donetsk, a city of about 1 million people, is a major center of the separatist uprising that has battled Ukrainian government forces for five months.

An Associated Press reporter found the highway north of Donetsk blocked by rebels and heard the sound of artillery to the north. Explosions were heard in the direction of the town's airport, on the northwest edge of the city, an area frequently contested by Ukrainian forces and rebels. Black smoke rose from the direction of Yakovlikva, a northern suburb of Donetsk.

Families visit site

About 60 km to the east, the site where Malaysia Airlines Flight MH17 was shot down was still eerily empty except for the parents of one of the 298 people killed in the July 17 disaster. A full-fledged investigation still hasn't started because of the security risks posed by the nearby fighting.

But Jerzy Dyczynski and Angela Rudhart-Dyczynski, parents of 25-year-old Fatima, traveled from their home in Perth, Australia, to honor their daughter. They crossed territory held by rebels to reach the wreckage-strewn fields outside the village of Hrabove, where they sat together on part of the debris, his arm around her shoulder.

Fatima "was for peace. She will be forever for peace", her father said.

US and Ukrainian officials said the plane was shot down by a missile from rebel territory, most likely by mistake.

The disaster sparked hopes in the West that Russia would scale back its involvement in the uprising in Ukraine's east, but nine days later the opposite seems to be the case.

Russia launched artillery attacks from its soil into Ukraine on Friday, while the US said it has seen powerful rocket systems moving closer to the Ukraine border.

Those accusations sparked a strong denial from Moscow, which accuses the US of a smear campaign.

EU sanctions

The Russian Foreign Ministry accused the US on Saturday of conducting "an unrelenting campaign of slander against Russia, ever more relying on open lies".

Russia also lashed out at the latest round of Ukraine-related sanctions imposed by the European Union, saying they endanger the fight against international terrorism.

The EU sanctions, announced on Friday, impose travel bans and asset freezes on 15 people, including the head of Russia's Federal Security Service. Four members of Russia's national security council are also on the list.

The Foreign Ministry said the sanctions show the EU is taking "a complete turn away from joint work with Russia on international and regional security, including the fight against the spread of weapons of mass destruction, terrorism (and) organized crime".

(China Daily 07/28/2014 page12)