Russia and Ukraine struck at each other's capitals in the early hours of Thursday, hours after American-mediated peace talks ended without agreement on the questions at the heart of the war.

Explosions were heard across Kyiv in the early hours of the morning, according to a Reuters witness in the city. There was no immediate word on whether the Ukrainian capital had suffered damage.

In Moscow, the city's mayor, Sergei Sobyanin, said air defences had brought down five drones heading for the Russian capital. Writing on Telegram, he gave no further details about the attack or any damage.

Talks end with prisoner swap agreed

The overnight strikes came a day after negotiators from Russia and Ukraine finished two days of talks in Abu Dhabi. The two sides agreed to exchange prisoners, but American mediators said wide differences remained on major issues, including questions over territory.

The talks were the latest attempt by Washington to broker an end to the war, which has lasted almost five years. Neither side has yet signalled a breakthrough on the territorial questions that have blocked every previous round.

US envoys head to Moscow

American envoys Jared Kushner and Steve Witkoff were due to travel to Moscow on Thursday for talks with President Vladimir Putin. They are expected to raise the question of bringing European partners into the negotiations, something Mr Kushner has said must happen.

The two envoys then plan to fly to Ireland to meet President Volodymyr Zelenskyy, who is due to attend a gathering of European leaders there. The Dublin meeting is expected to focus heavily on Ukraine and on Europe's place in any settlement.

Kyiv sees hope of a deal this year

A senior Ukrainian official said the Abu Dhabi talks had created momentum for an agreement before the end of the year. David Arakhamia, a senior member of Mr Zelenskyy's party, said the two sides had good momentum to reach a solution before the new year and that the fighting could end this year.

American mediators struck a more cautious note, warning that trust between the two sides was lacking. Yuri Ushakov, a foreign policy adviser to Mr Putin, described the two days of talks as substantial and useful.

Ukraine's military said on Wednesday that its drones had struck the Russian Baltic port of Ust-Luga, a key point for shipping oil products, setting off a fire and damaging part of its network of storage tanks. The strike was part of a sustained Ukrainian campaign against Russian energy infrastructure.

Russia launched its full-scale invasion of Ukraine in February 2022. Since then, both capitals have repeatedly come under attack, but strikes on Kyiv and Moscow on the same night remain relatively rare, and they carry a symbolic weight beyond any physical damage.

The exchange of fire over the two capitals underlined how the fighting continues even as diplomacy gathers pace, with both sides still seeking to strengthen their positions before any settlement is reached.