Sirens wailed overnight in nearly all of the country, as the attacks killed two people in the Poltava region, with Zaporizhzhia, Kherson and Kharkiv each reporting one death.

On the eve of the strikes, Ukrainian President Volodymyr Zelensky had warned in his daily televised address that "there is information from our intelligence that the Russians may be preparing a massive strike".

A 61-year-old passenger on an electric train in Kharkiv "died on the spot" after the train was hit at around 5:20 am (0320 GMT) by a drone, according to the Kharkiv Regional Prosecutor's Office.

The strikes also "killed a civilian resident of Kherson in his own home", Yaroslav Shanko, head of the Kherson city military administration, said.

Media outlet Suspilne Poltava published images on Tuesday morning showing residential buildings with blown-out windows and scorched facades.

Two people were killed and seven wounded in the Poltava region, emergency services said.

Farther south, Russia carried out a "massive combined missile-drone strike" in Zaporizhzhia, according to Ivan Fedorov, head of the regional military administration, with emergency services reporting one person killed and five wounded.

Russia attacked two districts of the Dnipropetrovsk region "with drones and artillery more than 20 times", according to Oleksandr Ganzha, head of the regional military administration.

"A 76-year-old woman was wounded" and hospitalised, Ganzha posted on Telegram.

In Sumy, a 65-year-old driver of an empty minibus was injured when his vehicle was hit by a drone, according to the head of regional military administration Oleg Grygorov.

Separately, Russia's defence ministry said on Tuesday that its air defences intercepted "55 Ukrainian fixed-wing unmanned aerial vehicles" over various regions in the preceding night.