Ukrainian forces were reportedly advancing on rebel positions near the key eastern town of Donetsk on Saturday, as they try to retake the separatist stronghold.
Donetsk is the region where Malaysia Airlines MH17 was shot down on July 17, killing nearly 300 people. Pro-Russian rebels have been blamed for downing the plane and they have hampered international efforts to access the site of the wreckage.
The Washington Post says: "Government troops are currently battling rebels in the nearby town of Horlivka and have blocked all roads leading out of Donetsk to prevent the insurgents from replenishing supplies and fighters or escaping, said Andriy Lysenko of the Ukrainian Security and Defense Council. Once Horlivka is under Ukrainian control again, he said, the army will move to retake Donetsk, a city where pro-Russian separatists have held sway for months while declaring it the Donetsk People's Republic. The Ukrainian military has ousted rebels from 10 surrounding villages and towns in the past week."
According to the AP, 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 becoming more involved in the fighting, with the U.S. and Ukraine accusing Moscow of moving heavily artillery across the border to the rebels."
As we reported earlier this week, the U.S. has said it has "new evidence" that Russian forces were lobbing artillery across the border and that Moscow was planning to ship powerful multiple rocket launcher systems to the pro-Russian separatists fighting in eastern Ukraine.
NPR's Corey Flintoff, reporting from Donetsk, says Ukrainian officials have been accusing Russian troops for days of firing across the border
"The allegations come as separatists appear to be losing ground in the face of a Ukrainian offensive," Corey says.