KYIV, Ukraine (AP) -- Journalists packed a small courtroom in Kyiv for the trial of a captured Russian soldier accused of killing a Ukrainian civilian in the early days of the war -- the first of dozens of war crimes cases that Ukraine's top prosecutor said her office is pursuing.
As the trial of 21-year-old Russian Sgt. Vadim Shyshimarin got underway in the capital, Russian forces suffered heavy losses in a Ukrainian attack that destroyed a pontoon bridge they were using to try to cross a river in the east, Ukrainian and British officials said in another sign of Moscow's struggle to salvage a war gone awry.
Ukraine's airborne command released photos and video of what it said was a damaged Russian pontoon bridge over the Siversky Donets River in Bilohorivka and at least 73 destroyed or damaged Russian military vehicles nearby.
Britain's Defense Ministry said Russia lost "significant armored maneuver elements" of at least one battalion tactical group in the attack. A Russian battalion tactical group consists of about 1,000 troops.
"Conducting river crossings in a contested environment is a highly risky maneuver and speaks to the pressure the Russian commanders are under to make progress in their operations in eastern Ukraine," the ministry said in its daily intelligence update.
In other developments, a move by Finland and, potentially, Sweden to join NATO was thrown into question when Turkish President Recep Tayyip Erdogan said his country is "not of a favorable opinion" toward the idea. He accused Sweden and other Scandinavian countries of supporting Kurdish militants and others Turkey considers terrorists.
Erdogan did not say outright that he would block the two nations from joining NATO. But the military alliance makes its decisions by consensus, meaning that each of its 30 member countries has a veto over who can join.
An expansion of NATO would be a blow to Russian President Vladimir Putin, who undertook the war in what he said was a bid to thwart the alliance's eastward advance. But in the wake of the invasion of Ukraine, other countries along Russia's flank fear they could be next.
With Russia's offensive in the Donbas, Ukraine's eastern industrial heartland, seeming to turn increasingly into a grinding war of attrition and Ukraine pleading for more arms to fend off the better-equipped Russians, the European Union's foreign affairs chief announced plans to give Kyiv an additional 500 million euros ($520 million) to buy heavy weapons.
Ukrainian Defense Minister Oleksii Reznikov welcomed the heavy weapons making their way to the front lines but admitted there is no quick end to the war in sight.
"We are entering a new, long-term phase of the war," he wrote in a Facebook post. "Extremely difficult weeks await us. How many there will be? No one can say for sure."
The battle for the Donbas has turned into a village-by-village, back-and-forth slog with no major breakthroughs on either side and little ground gained. In his nightly address Friday, Ukrainian President Volodymyr Zelenskyy said no one can predict how long the war will last but that his country's forces have been making progress, including retaking six Ukrainian towns or villages in the past day.
Fierce fighting has been taking place on the Siversky Donets River near the city of Severodonetsk, said Oleh Zhdanov, an independent Ukrainian military analyst. The Ukrainian military has launched counterattacks but has failed to halt Russia's advance, he said.
"The fate of a large portion of the Ukrainian army is being decided -- there are about 40,000 Ukrainian soldiers," he said.
The Ukrainian military chief for the Luhansk region of the Donbas said Friday that troops have taken nearly full control of Rubizhne, a city with a prewar population of around 55,000.
In the ruined southern port of Mariupol, Ukrainian fighters holed up in a steel plant faced continued Russian attacks on the last stronghold of resistance in the city. Sviatoslav Palamar, deputy commander of Ukraine's Azov Regiment, said his troops will hold out "as long as they can" despite shortages of ammunition, food, water and medicine.
And in Kyiv, Ukrainian soldiers dressed in white protective suits loaded the bodies of Russian soldiers onto refrigerated train cars on Friday. The bodies were wrapped in white body bags and stacked several layers deep.
Col. Volodymyr Lyamzin, who supervised the operation, said several hundred bodies were being stored on the trains in the capital and that there were several other storage trains elsewhere in the country. He said Ukraine was ready to hand the bodies over to Russia, but so far there has been no agreement to do so.
In the first war crimes case brought to trial, Shyshimarin could get life in prison if convicted of shooting a 62-year-old Ukrainian man in the head through an open car window in a village in the northeastern Sumy region on Feb. 28, four days into the invasion.
The defendant, dressed in a blue and gray hoodie and gray sweatpants, sat in a small glass cage during the proceedings, which lasted about 15 minutes and will resume on Wednesday. The trial will be closely watched by international observers to make sure the trial is fair.
Shyshimarin was asked a series of questions, including whether he understood his rights and whether he wanted a jury trial. He declined the latter.
His Ukraine-assigned attorney, Victor Ovsyanikov, has acknowledged that the case against Shyshimarin is strong and has not indicated what the soldier's defense will be.
Shyshimarin, a member of a tank unit that was captured by Ukrainian forces, admitted that he shot the civilian in a video posted by the Security Service of Ukraine, saying he was ordered to do so.
Ukrainian Prosecutor General Iryna Venediktova said she is readying war crimes cases against 41 Russian soldiers for offenses including bombing civilian infrastructure, killing civilians, rape and looting. She said two accused of bombing civilian infrastructure and residential buildings are in Ukrainian hands. It wasn't clear how many of the suspects would be tried in absentia.