A top separatist leader on Saturday admitted that Ukrainian forces had surrounded Donetsk, the stronghold of Russian-backed rebels, and called for a ceasefire on humanitarian grounds.
"We are ready for a ceasefire in order to avert the humanitarian catastrophe growing," Alexander Zakharchenko, prime minister of the self-styled Donetsk People's Republic, said in a statement posted on a rebel website, according to the Associated Press and AFP news agency.
Igor Girkin, a top commander of the pro-Russia militants, also acknowledged Saturday that Donetsk was surrounded and conceded that Ukrainian troops had gotten the upper hand in eastern Ukraine after four months of fighting.
The appeal by Zakharchenko comes as Russia is pressing to send a humanitarian convoy into Ukraine to parts of the besieged eastern regions, an offer that the Ukrainian government has labeled a ploy to cover a military invasion.
Although Western countries says Moscow has assembled some 20,000 troops just across the border, Russia has denied it .
Zakharchenko -- who took over as prime minister of of the DPR last week -- warned that rebels were determined the defend Donestk if Ukrainian forces tried to capture the city of one million people.
"The fight will be for every street, for every house, for every meter of our land," Zakharchenko said, and would turned the city into a new "Stalingrad," a reference to the Soviet Union's refusal to surrender the city of Stalingrad to the Nazis during World War II.
Zakharchenko acknowledged that the situation was "difficult and tense" but said "the troops' morale is strong," the AFP news agency reports.
A spokesman for the Donetsk city administration said at least one person was killed and several injured in shelling of the city's southern area on Saturday. Spokesman Maxim Rovninsky also told the AP that about 30 apartment blocks came under fire during the night. Explosions were also heard Saturday on the northern outskirts near the city's airport. Ukrainian officials denied that they are shelling civilians.
The Ukrainian Foreign Ministry on Saturday strongly objected to Russia sending a "humanitarian convoy" over the border into eastern Ukraine.
"Bearing in mind numerous violations by the Russian Federation of the state border regime of Ukraine and continued illegal supply of weapons, armored vehicles and mercenaries from Russia, Ukraine has solid grounds for concerns that the convoy may trigger further escalation and lead to deterioration of the situation for the people in Donbas," the ministry said in a statement said, according to Ukrinform.
The International Committee of the Red Cross has acknowledged the Russian proposal to organize aid convoys and said "any humanitarian initiative is welcome" but added that any Red Cross "action will be taken in strict adherence to our fundamental working principles of neutrality, impartiality, and independence."
Russia's Foreign Minister Sergei Lavrov spoke with U.S. Secretary of State John Kerry Saturday and called for "urgent measures for preventing an impending humanitarian catastrophe" in eastern Ukraine, the Foreign Ministry said in a statement. It added that Kerry "confirmed such work is being carried out with the Kiev authorities."
Girkin, who is also known as Strelkov, also said the town of Krasnyi Luch, which lies on one of the two main roads between Donetsk and the rebel-held east's other main city of Luhansk, "has been taken by the enemy."
A spokesman for the Ukrainian military operation, Andriy Lysenko, told reporters Saturday that he could not confirm that Krasnyi Luch was under the control of Ukrainian forces.
In Luhansk, which is in far eastern Ukraine about 20 miles from the Russian border, the city council said in a statement Saturday that its situation remains critical, with the city going without electricity, water, or most communications for a week. The report said only about 250,00 people remain in the city with a normal population of 425,000.
"Most of the shops are closed, only a few pharmacies are open. Despite the absence of electricity Luhansk bakeries continue to work," the council's report said, according to Interfax-Ukraine. "Fuel reserves have been exhausted, there are no new supplies," the report reads.
A family of five was killed in Luhansk after the basement they were living was hit by shells allegedly fired by Ukrainian troops, RT.com, the Russian News agency reports.
"Grown men were in tears, as the fierce fire burned, others pleaded to try and help the family, which was trapped," the Russian news agency said. "However, there was little that anyone could do and eventually five charred bodies were dragged out of the ruins as the flames began to ease."
In Kiev, meanwhile, city workers and volunteers on Saturday removed the last of the barricades that had blocked the main street of Ukraine's capital since protests that forced a change of government arose late last year.
Protesters erected the barricades to protect a sprawling tent camp on the central city's main square. Although the camp's size dwindled sharply after President Viktor Yanukovych fled the country in February and a new government came to power, a determined core of demonstrators remained in a show of suspicion of the new authorities.
Some tents remained on Saturday. But Kiev mayor Vitali Klitschko, who was one of the leaders of the protests against Yanukovych, was quoted by Ukrainian media as saying an agreement has been reached with the protest holdouts to restore free movement in the center.
Yanukovych's ouster precipitated the crisis in Ukraine's east, which was his support base and where many were opposed to the new authorities, calling them nationalists with fascist leanings who intended to oppress the largely Russian-speaking east.
Contributing: Associated Press
Follow Doug Stanglin on Twitter: @dstanglin