Ukraine’s military repelled a wave of rebel assaults on Donetsk Airport yesterday, rushing in new troops and ammunition to the battle zone as the government prepares for a visit by neighboring Poland’s prime minister.

Pro-Russian separatists created an “epicenter of tension” as they used artillery, mortars and rifle fire in a bid to pry government troops from their tenuous hold on the strategically important site, authorities in the capital Kiev said. Three Ukrainian servicemen were killed and 18 were wounded in the first 24 hours of the weekend, military spokesman Andriy Lysenko said yesterday in Kiev.

“The confrontation is ongoing at Donetsk airport,” Lysenko said. “Militants attacked Ukrainian positions near the new terminal and weather tower. Ukrainian soldiers are repelling the attacks by the terrorists.”

The week-long effort by separatists to take the regional airport rekindles the prospects of all-out war in the former Soviet republic. More than 4,800 people have died in the nine- month conflict, which has poisoned Russia’s ties with its former Cold War foes. Russia rejects accusations by Ukraine, the U.S., the European Union and the North Atlantic Treaty Organization that it’s meddling in the conflict by sending troops and weapons.

Polish Prime Minister Ewa Kopacz will land in Kiev tomorrow to meet with her Ukrainian counterpart Arseniy Yatsenyuk, according to the Ukrainian government’s website. Poland has been the most vocal European Union supporter of the Ukrainian government that emerged from last year’s street protests that led to the ouster of former President Viktor Yanukovych.

With the cancellation last week of peace talks planned in Minsk, the capital of neighboring Belarus, and Astana in Kazakhstan, fighting has picked up. Lysenko said military officials recorded a wave of 82 separate attacks by militants earlier on the weekend.

Pro-Russian fighters shelled residential areas near the airport yesterday with artillery and multiple-launch Grad rocket systems after attacks on the airport were turned back, the Security Council said on the website. Russian-made Grads were also used in residential areas in the Luhansk region, the council said. Government positions and residential areas were attacked 19 times by 2 p.m. yesterday.

Russia is amassing troops and armaments at the border with Ukraine and is testing new weapons in the conflict area, Lysenko said. Government soldiers were struggling to evacuate the wounded from the airport as a “fierce fight” resumed yesterday afternoon, the Security and Defense Council said on its website.

The government ordered roads closed for bus and truck traffic in the Luhansk region while insurgents attacked civilians, Luhansk Regional Governor Hennadiy Moskal said on his website. One civilian was killed and four wounded yesterday after militants shelled the town of Popasna at 3 p.m., he said.

Fighting ruined homes, commercial structures and infrastructure in several other villages in the Luhansk region. Workers who were mending a damaged gas pipeline were fired upon yesterday, Moskal said.

Metinvest Holding’s Avdiyivskyi coke plant, owned by Ukraine’s richest man, Rinat Akhmetov, was hit by artillery fire today, injuring three workers, Chief Executive Officer Musa Magomedov reported on his Facebook page.

The plant was closed after artillery damaged the factory’s main sections, Magomedov said. Avdiyivskyi, about 3 miles north of Donetsk airport, has endured almost constant artillery and mortar shelling since July, according to its website.

Ukrainian President Petro Poroshenko and German Chancellor Angela Merkel have called for an immediate meeting of the contact group that includes Ukraine, Russia and the Organization for Security and Cooperation in Europe.

A gathering of the contact group should be followed by a meeting of French, German, Ukrainian and Russian foreign ministers, Poroshenko said in a statement on his website after a phone talk with Merkel.

The key pre-conditions for further peace talks are the closure of the Ukrainian-Russian border, the withdrawal of heavy weaponry and the release of all hostages, according to the statement.

Merkel said on Jan. 14 that there is insufficient agreement between Russia and Ukraine to hold a multi-nation summit.

Explosions in Odessa, on the Black Sea coast, and a fire that engulfed a rail tank car carrying gasoline in the Kharkiv region added to tensions. The local prosecutor’s office called the blaze an act of sabotage. In addition, nine passenger cars were damaged by an explosion in a residential area in Kiev late yesterday.

More than 40 towns and villages in the Donetsk region, mainly near the airport, remain without electricity, Lysenko said.