DONETSK, Ukraine — After days of street battles and weeks of shelling, Ukrainian troops made significant gains Wednesday into rebel-held territory, capturing a large part of the city of Luhansk and nearly encircling Donetsk, the largest rebel-held city, in fighting that left at least 52 dead.
Ukrainian troops have been trying for weeks to drive the rebels out of Luhansk and cut off Donetsk, a city of 1 million that has shrunk by a third as frightened residents fled. In the last few days, several neighborhoods in Donetsk have been hit with artillery fire and fighting on the city's outskirts has become more intense.
Andriy Lysenko, a spokesman for Ukraine's National Security Council, told reporters Wednesday in Kiev that government forces were now in control of "significant parts" of Luhansk, an eastern city just 20 kilometers (12 miles) from the Russian border.
Hard-hit Luhansk has been without electricity, running water or phone connections for 18 days due to the fighting between government forces and pro-Russia separatists. Russia has sent a massive aid convoy to help the residents there but it's still stuck at the border, not yet approved by Kiev because its proposed route lies through rebel-held territory.
Ukraine has accused Russia of arming and supporting the rebels, a charge that Russia denies.
Earlier in the day, Luhansk city authorities reported running battles between the two sides.
The death toll mounted quickly Wednesday. In Donetsk, the regional administration said 34 local residents were killed and 29 wounded in the last 24 hours as of noon. Another 9 people were killed and 13 wounded in afternoon shelling, the Donetsk mayor's office said.
Lysenko, the government spokesman, said nine troops were killed and 22 wounded in overnight fighting in Ilovaysk, a town near Donetsk, as the government sought to retake a major railroad and a highway that leads to Russia. He said fighting continued Wednesday in Ilovaysk even though government forces had gained control of the town.
Among those killed in Ilovaysk was a Ukrainian-American known by the nom de guerre of "Franko," said Anton Herashchenko, an adviser to the interior minister. He said Franko was an American citizen with a military background who had been living in eastern Ukraine for 10 years and obtained Ukrainian citizenship before joining the government side.
For several weeks running, Donetsk has come under daily shelling attacks from all sides. The imprecision of the shelling is creating much animosity while seemingly taking a limited toll on rebel forces.
On Wednesday morning, rockets slammed into residential areas, including the suburb of Makiivka.
"I was with my grandmother in the bathroom, because there is a bearing wall in there," said Anna Zyukova, 22. "And then all of sudden, bam-bam."
Many Donetsk residents have been taking refuge in improvised bomb shelters in apartment building basements. Residents in Makiivka huddled in groups near one such shelter Wednesday, chatting and listening as rockets flew in and out several miles away.
At a rebel camp closer to the fighting, a rebel commander who identified himself only as "Chaika" — Russian for seagull — said he was at a loss to explain why army shells were hitting apartments.
"We purposely don't take up positions where people live," he said — a claim that Ukrainian officials have repeatedly dismissed.
The fighting began a month after Russia annexed Ukraine's Black Sea peninsula of Crimea.
The Kiev government also is pursuing diplomatic efforts to resolve the conflict, which the United Nations says has killed more than 2,000 people and displaced over 340,000 since the fighting began in mid-April.
Ukrainian President Petro Poroshenko will host German Chancellor Angela Merkel this weekend in Kiev before meeting next week with Russian President Vladimir Putin in Minsk, the capital of Belarus.
In Moscow on Wednesday, protesters scaled one of the city's famed Stalin-era skyscrapers and painted the Soviet star on its spire in the national colors of Ukraine. They also attached a yellow-and-blue Ukrainian flag to the top of the 176-meter (580-foot) building.
While Moscow police detained four suspects and charged them with vandalism, a crime punishable with up to three years in prison, Poroshenko, the Ukrainian president, welcomed the flag-hoisting over the skyscraper in a video message, calling it a "symbolic" gesture.
He urged Ukrainians all over the world to fly Ukrainian flags at their homes in celebration of the country's Independence Day holiday on Sunday.
Vasilyeva reported from Kiev, Ukraine. Lynn Berry in Moscow contributed to this report.