Ukrainian drones struck Russia’s Black Sea port of Tuapse on Friday for the fourth time in 16 days as authorities struggled to cope with a growing environmental disaster from toxic black smoke clouds and oil leaking into the sea. Ukraine’s SBU security service said drones had again struck the seaport and refinery that make Tuapse an important hub for Russian oil exports. Local Russian officials said a major operation was under way to put out a fire at the port but no casualties were reported. The refinery has been hit and set ablaze at least twice since 16 April, halting production, in attacks that have thrown up dense black clouds over the town and caused oil slicks along the coastline, ruining the beaches of the popular resort.

Russian authorities had so far cleared more than 13,300 cubic metres of fuel oil and contaminated soil along the coast, they said on Friday. State TV showed a reporter standing on a blackened beach and using a spade to show how deep the oozing filth had seeped.

Russia launched almost 410 drones at Ukraine in a daytime attack that including injuring 10 people in the western city of Ternopil, Ukrainian officials said on Friday. Air force units downed or neutralised 388 of them in the north, south, centre and west of the country, Ukraine’s air force said. In Ternopil, about 150-200km from the Polish border, 10 people were hurt in the attack, which hit industrial and infrastructure facilities, the city’s mayor said.

In central Ukraine, 19 drones were downed over the Cherkasy region, the regional governor said, reporting damage to a nursery, a school, seven private houses and a power line. A woman was hurt in the central Vinnytsia region, the local governor said, adding that a building was destroyed. Near the southern city of Odesa, which had come under the overnight attack, another daytime attack damaged the roof of a shopping centre and caused a fire, the regional governor said, while Zelenskyy said at least five people were wounded in the region.

Ukraine has announced plans to carry out reforms of the army this summer to address problems with infantry shortages and the discharge of the longest-serving soldiers, four years into the war with Russia. Manpower shortages have become an even more pressing issue as enthusiasm for service has waned amid reports of poor training and support, as well as heavy-handed draft officers. “Now, in May, all key details will be finalised,” Zelenskyy said on Telegram on Friday. “In June, the reform will begin – and the first results must already be delivered in June.” He promised higher pay for the infantry, saying: “A Ukrainian infantryman who holds the front line must feel that our state truly respects him.” Ukraine had to be ready to fight on if a peace deal could not be reached, Zelenskyy said. Mykhailo Fedorov, who was named defence minister in January, said the changes announced amounted to a “systemic” transformation of the army.

Public prosecutors in Peru said they were investigating an alleged trafficking network offering fake jobs in Russia to Peruvians before forcing them to fight in Moscow’s war on Ukraine. Individuals including former military personnel and police officers were allegedly recruited through social media with deceptive offers of well-paid work as security agents and other jobs in Russia, the attorney general’s office said. According to information provided to the police, “victims were reportedly taken to Russia and, once on foreign soil, forced to take part in combat operations in the context of the armed conflict between Russia and Ukraine”, it said. Thirteen Peruvians had died in the Ukraine war, a lawyer for the victims’ families told local media.