Ukraine has accused Moscow of forcibly taking thousands of civilians from the shattered port city of Mariupol to Russia so that they can be used as "hostages" to pressure Kyiv to give up.
A month into the invasion, meanwhile, the two sides traded heavy blows in what has become a devastating war of attrition. Ukraine's navy said it sank a large landing ship near the port city of Berdyansk that had been used to supply Russian forces with armoured vehicles.
Russia claimed to have taken the eastern town of Izyum after fierce fighting.
At an emergency Nato summit in Brussels, Ukrainian President Volodymyr Zelenskyy pleaded with the Western allies via video for planes, tanks, rockets, air defence systems and other weapons, saying his country is "defending our common values".
US President Joe Biden, in Europe for a series of summits, gave assurances more aid is on its way.
Nato Secretary-General Jens Stoltenberg said the alliance's leaders agreed to send equipment to help protect Ukraine against chemical attacks. Around the capital, Kyiv, and other areas, Ukrainian defenders appear to have fought Moscow's ground troops to a stalemate, raising fears that a frustrated Russian President Vladimir Putin will resort to chemical, biological or nuclear weapons.
Ukraine's Foreign Ministry charged that Russian forces have taken 6000 Mariupol residents to camps against their will. Russian troops are confiscating identity documents from an additional 15,000 people in a section of Mariupol under Russian control, the ministry said.
Ukrainian military intelligence said Ukrainian civilians are being sent through a camp in Russian-controlled territory, then onward through southern regions of Russia to economically depressed parts of the country.
Some could be sent as far as the Pacific Ocean island of Sakhalin, Ukrainian intelligence said, and are being offered jobs on condition they don't leave for two years. The claims could not be independently verified. Russia has said it is evacuating thousands of civilians of their own free will.
Photos and videos after the naval attack in Berdyansk showed fire and thick plumes of smoke. Russian TV reported earlier this week that the vessel the Ukrainians claimed to have sunk, Orsk, was the first Russian warship to enter Berdyansk. The port was going to be used to deliver military equipment for the Russians, the report said.
Ukraine claimed two more ships were damaged and a 3000-ton fuel tank was destroyed when the Orsk was sunk, causing a fire that spread to nearby ammunition supplies.
Sending a signal that Western sanctions have not brought it to its knees, Russia reopened its stock market but allowed only limited trading to prevent mass sell-offs. Foreigners were barred from selling, and traders were prohibited from short selling, or betting prices would fall.
Millions of people in Ukraine have made their way out of the country, some pushed to the limit after trying to stay and cope.
At the central station in the western city of Lviv, a teenage girl stood in the doorway of a waiting train, a white pet rabbit shivering in her arms. She was on her way to join her mother and then go on to Poland or Germany. She had been traveling alone, leaving other family members behind in Dnipro.
"At the beginning, I didn't want to leave," she said. "Now I'm scared for my life." — AP