As the war enters its 663rd day, these are the main developments.

Fighting

• Ukraine’s Air Force said it destroyed 20 Russian drones and a missile – nine of them in the southern Odesa region. The falling debris started a fire in a residential home and killed one person. The air force said a second missile “did not reach its goal”. On Saturday, Ukraine said its air defence systems shot down 30 Russia-launched drones over 11 regions of the country
• Russia’s Defence Ministry said its air defence systems destroyed or intercepted a total of 35 Ukraine-launched drones over its Lipetsk, Volgograd and Rostov regions in Russia. It did not say what was targeted or whether there was any damage. The Ukrainska Pravda media outlet later reported that the attack – reportedly a joint operation of the Security Service of Ukraine (SBU) and Ukraine’s Armed Forces – was targeting the Morozovsk airfield in the Rostov region. Several Russian military bloggers said that one bomber at the base suffered minor damage.
• The Freedom of Russia Legion, a Ukrainian-based paramilitary group of Russians who oppose President Vladimir Putin, said it was behind a cross-border attack inside Russia’s Belgorod region. The group said it had destroyed a platoon stronghold of Russian troops near Trebreno village and planted mines, but did not elaborate. Vyacheslav Gladkov, Belgorod’s regional governor, said Trebreno was under fire from Ukraine’s Armed Forces and that a “shooting battle” was under way on the edge of the village. He said three houses and a power line were damaged.

• The Associated Press news agency published drone footage indicating the scale of Russian casualties in the intense battles for control of the eastern Ukrainian city of Avdiivka. The footage showed the bodies of about 150 soldiers – most of them in Russian uniforms – lying on the ground where they died outside Stepove, a village north of Avdiivka, that has been reduced to rubble. The drone unit said it is possible that some of the dead were Ukrainians.
• Family and friends of Ukrainian soldiers from the so-called Azov battalion held captive by Russia since the fall of Mariupol held a rally in Kyiv calling for their urgent exchange with Russian prisoners of war.

Politics and diplomacy

• Ukraine’s security service said it had launched a criminal investigation after a “technical device” was found in an office that could have been used in the future by Commander-in-Chief Valery Zaluzhnyi. It added that the device – initially characterised as a bug by local media – was considered under preliminary information to be “in a non-operational state”, and no means of information storage or remote transmission of audio recordings were found.
• Ukrainian President Volodymyr Zelenskyy said Ukraine and the European Commission would soon assess Kyiv’s progress on aligning its legislation with that of the European Union. A framework for negotiations on Ukraine’s EU accession is also expected in the coming months, he added in his nightly video address.
• Putin dismissed as “complete nonsense” remarks by United States President Joe Biden that Russia would be emboldened to attack a NATO country if it was successful in its invasion of Ukraine. Putin said Russia had no interest in fighting the NATO military alliance. Biden stressed the threat posed by Moscow in an appeal to Republican lawmakers resisting new support for Kyiv.
• A senior US congressional negotiator working over the weekend to craft a deal that would be acceptable to its critics said he was “very optimistic” about a solution. The Republicans have demanded the aid to Ukraine and Israel be linked to new measures at the US’s southern border. “I’m very encouraged. I’m very optimistic they’re moving in a very positive way,” Joe Manchin, a Democrat, told CNN’s State of the Union program.
• Police in Finland are seeking a court order to imprison a Russian man accused of committing war crimes against wounded or surrendered soldiers in eastern Ukraine in 2014 and 2015. Yan Petrovsky, who had been living in Finland under the name Voislav Torden, is already in Finnish custody but authorities are asking that he be formally jailed while they conduct an investigation into his alleged crimes.