The Ukrainian authorities on Monday said that they had repelled a “massive” Russian attack on Kyiv in the early morning hours. They said it was the eighth attack on the Ukrainian capital in just over two weeks, in what appears to be an escalation by Russia of its long-running air campaign against the city.

Serhii Popko, the head of Kyiv’s military administration, said that Ukrainian forces had shot down nearly two dozen Russian drones around Kyiv, and the Ukrainian air force said it had intercepted 53 of 56 Russian drones overnight.

Mr. Popko said that in contrast to recent attacks, “this one was massive,” and that an air-raid alert was announced about 2 a.m. in the capital and remained in effect for about three and a half hours.

The Ukrainian military’s claims could not be independently verified, and there was no comment from the Russian authorities.

One woman was injured by debris from a downed drone, the authorities said, but they reported no significant damage in the capital. The Ukrainian government did acknowledge, however, that shelling of energy infrastructure in five other regions had caused temporary power cuts over the past day.

Russia has been intensifying its assaults on the Ukrainian capital and other big cities since the beginning of the month, starting with an assault on Sept. 2, on the first day of the school year, when Russia fired a volley of missiles at Kyiv and other cities.