Ukraine's air force said on Sunday evening that the official application Ukrainians use to be warned of Russian air strikes had "probably been the victim of hostile interference." The statement was issued shortly after the expiry of a localized humanitarian truce in the town of Olechky.

Ukraine's Center for Countering Disinformation said the "Air Alert" app had probably been hacked and that the threat-level information being circulated did not correspond to reality. The warning followed the appearance on the application of messages referring in particular to a nuclear radiation threat and to chemical threats.

The truce around Olechky, a Russian-occupied town on the front line in the southern Kherson region, ended at 22:59 local time (21:59 in Paris) on Sunday. It had begun on Tuesday morning and was the longest ceasefire since the war began in February 2022. Unlike other partial ceasefires, notably around Orthodox Easter, neither Kyiv nor Moscow reported any violation of the arrangement.

Ukraine's human rights ombudsman, Dmytro Loubinets, said on Telegram that the parties had respected their commitments during the period, which made it possible to deliver humanitarian aid to Olechky and to help civilians who wanted to leave the city safely. He added that he was now working with his Russian counterpart, Iana Lantratova, on new "humanitarian initiatives."

Nearly 700 residents of Olechky were evacuated on Saturday towards northern Ukraine after a humanitarian operation, travelling by bus or by plane via Russia and then Belarus. President Volodymyr Zelensky thanked the American delegation and US first lady Melania Trump for their mediation.

An hour before the truce expired, Russia's defense ministry wrote on Telegram: "We don't spare ammunition, nor the enemy. The night will be hot, we're at work." Pope Leo XIV, who had himself supported the idea of a humanitarian truce in Olechky, said he hoped the cooperation between Kyiv and Moscow "will strengthen the will for dialogue and lead to new concrete initiatives in favour of peace."

Separately, Zelensky said Ukraine would stop striking Russian refineries, as demanded by President Donald Trump, if Washington supplied Kyiv with Patriot interceptor missiles. Speaking on Fox News, he said he had held "several different conversations" with the US president and his team on the subject, and that Ukraine's position was that Russian energy sites should not be attacked if its own energy system is spared, with Patriot deliveries as an alternative. He said that if Washington provided the air-defense systems for a month, Kyiv would halt its attacks on refineries for the same period, and that he had no concern about the impression of pressure, saying he had none "when I share the truth between partners."

The US State Department said the Trump administration approved on Friday the sale of 500 Patriot missiles to Ukraine, but Zelensky warned that deliveries could take years, while Ukrainian authorities have for weeks warned that their stocks are running out. The US president has demanded that both countries stop attacking each other's energy sites, against a backdrop of inflation driven largely by energy prices amid the conflicts in Iran and between Russia and Ukraine.

Overnight, the Lukoil refinery at Kstovo in the Nizhny Novgorod region, about 400 km east of Moscow and one of Russia's largest oil refineries with a capacity of roughly 17 million tonnes a year, or some 340,000 barrels a day, was hit by a Ukrainian drone attack that triggered a fire, according to several Ukrainian media outlets including the RBC news agency. Regional governor Gleb Nikitin reported a "massive drone attack," said an industrial enterprise in the Kstovo district had suffered "significant damage," that more than a hundred drones were destroyed and that there were no preliminary reports of casualties. He said a woman in a car had been injured by falling drone debris and had since returned home from hospital, and that temporary power cuts were possible during repair work. The regional press service urged motorists to fill up according to their needs to avoid creating artificial demand.

Ukraine's air force said Russia launched 433 drones from 18:00 on October 31, including Shahed types of which 64 were jet-powered, as well as Guerbara drones and Parodiia decoy drones, and that 371 had been shot down or neutralized by 7:30. Russia's defense ministry claimed to have intercepted 235 Ukrainian drones over about ten of its regions, a figure that could not be confirmed, and reported strikes on railway traffic control centres at Konotop station in the Sumy region. A day earlier, the Ukrainian military said it had downed or intercepted 122 drones and two S8000 Banderol missiles out of 168 drones and two missiles launched between 6:30 and 19:30.

In other developments, US Secretary of State Marco Rubio said on the sidelines of a G20 meeting in Atlanta that he had discussed with his Russian counterpart, Sergey Lavrov, a possible meeting between Donald Trump and Vladimir Putin at the Asia-Pacific Economic Cooperation summit scheduled for November 18 and 19 in China, suggesting the two leaders could meet in mid-November. Turkish President Recep Tayyip Erdogan received Zelensky in Istanbul on Saturday, after which the Ukrainian president said they had agreed to set up a Black Sea "grain corridor" to strengthen food security. Russian strikes also left some 200,000 households without electricity in the Dnipropetrovsk region and 80,000 in the Kyiv region, where a thermal power plant was hit by drones.

Sources: Le Monde International.