Fighting between government troops and Russia-backed separatist rebels in eastern Ukraine has escalated, killing at least eight people, injuring dozens and briefly trapping more than 200 coal miners underground, the warring sides report.

The unrest included the worst artillery shelling in months, in a conflict that has claimed more than 9,600 lives since it began in 2014.

Rebels in Donetsk said an electricity sub-station was damaged in shelling, cutting power to the Zasyadko coal mine and trapping 207 miners for several hours.

Separatist military spokesman Eduard Basurin, in an interview with Russian state television, denied reports that separatist shelling cut power lines and heating stations in the Avdiivka, a government-controlled town on the northern outskirts of the separatist stronghold of Donetsk, saying they had been damaged earlier.

Oleksandr Turchynov, chairman of the Ukrainian Security and Defence Council, said heavy shelling around Avdiivka killed at least three government troops and injured 24 more.

The Avdiivka coking plant in eastern Ukraine, currently in the path of fighting between government troops and separatist rebels. ( AP: Mstyslav Chernov, File )

The press office of the Ukrainian government's operation in the east reported an unspecified number of civilian casualties.

Dmitry Peskov, spokesman for Russian President Vladimir Putin, accused the Ukrainian Government of provoking the crisis.

Kiev-based independent political analyst Vadim Karasyov said an escalation in the east could be beneficial to both the separatists and the Ukrainian Government.

"Kiev is eager to win support of the new Trump administration, and for this they need to show that separatists and the Kremlin are derailing the peace accords," he said.

"For the Kremlin, it's important to show that it holds war and peace in its hands [and] if the new US administration wants peace in Ukraine, it needs to offer something in return."

Both sides in the conflict committed to cease fire and pull back heavy weaponry under a 2015 truce which they have violated several times.

Miners are evacuated from under the Zasyadko mine after shelling caused a power-cut in the rebel-held city of Donetsk. ( Reuters: Alexander Ermochenko )

AP