Vadym Filashkin, head of the regional military administration, said public transport in Kramatorsk and the neighbouring city of Sloviansk, in Ukraine's Donetsk region, was halted because of the sharp deterioration in security.
He accused Russia of deliberately targeting civilians, adding: "In such circumstances, we have no right to risk the lives of passengers and drivers. The safety of residents of Kramatorsk and Sloviansk is above all."
The attacks follow deadly missile strikes a day earlier in the northern Ukrainian town of Pryluky, where the death toll rose to 22, including five children.
Rescuers searched through the rubble of a residential building hit by a Russian missile and at least 54 people were injured.
Heavy debris was removed from the cratered section of the building, while rescue dogs continued a search nearby for residents who have not yet been accounted for.
Several survivors of the attack were forced to sleep in heavily damaged apartments after they could not find anywhere else to sleep.
Ukrainian President Volodymyr Zelenskiy warned that Russia would likely escalate daily missile and drone attacks as winter approaches.
He appealed for additional defence support from NATO countries.
"It is important that support in words takes concrete form in new packages for Ukraine's defence," he wrote in an online post.
"Supplies of anti-ballistic capabilities, ammunition for our combat aircraft, and investments in interceptors - all of this is directly helping save lives every day."
Ukraine's energy company DTEK said the national grid operator Ukrenergo had ordered emergency power outages in Kyiv.
It explained that this is separate from regular, rolling outages scheduled across the country and would not be applied during those shutdowns.
A public awareness campaign, restarted in October, urged families to prepare emergency kits, store drinking water and maintain off-grid power sources before expected prolonged winter blackouts, as Moscow keeps up the intensity of its attacks.
Kyiv police said bomb disposal specialists had defused two more unexploded ballistic missile warheads, each weighing about half a ton, after they landed near residential buildings.
Late on Wednesday, Russian drones struck Kyiv's Obolonskyi and Desnianskyi districts, killing four people and injuring 12, including four children, police said.
Russia and Ukraine are locked in a long-range aerial war while their armies remain largely deadlocked on the front line, more than four-and-a-half years since Moscow's full-scale invasion.
Russia's technology giant Yandex said one of its data centres in the western Ryazan region was damaged in a Ukrainian drone attack, taking the site offline and leading to potential online service disruption.
Separately, Ukraine said its forces struck a large oil refinery complex in the city of Salavat, some 1200km east of Moscow.
Ukraine's General Staff described the complex as one of Russia's largest oil refining and petrochemical facilities.
The claim could not be independently verified.
