Russian troops have intensified their offensive in Ukraine with a series of nighttime attacks in the eastern regions of Kharkiv and Donetsk.

Ukrainian military officials said on Friday that they had intercepted one missile and 24 out of 38 Iranian-made drones.

They say the attacks damaged a residential building, a service station and other facilities in Kharkiv, causing large-scale fires. Odesa in the country's south was also hit.

Russian forces also took aim at Avdiivka, a city in Donetsk.

Ukrainian troops are pushing on with their counteroffensive in the south. In a video address on Thursday, President Volodymyr Zelenskyy remained confident of driving Russia out.

The Institute for the Study of War, a US think tank, said on Thursday that Ukraine had launched a cruise missile attack on Russia's headquarters in the southern region of Kherson.

The same day, Britain's defense ministry said Ukrainian airstrikes have likely destroyed at least four of Russia's long-range surface-to-air missile launchers in Luhansk and Crimea.