Russian and Ukrainian forces launched cross-border drone attacks overnight Tuesday as Moscow began three days of nationwide nuclear weapons drills amid escalating tensions in the long-running war.

Ukraine's President Volodymyr Zelenskyy said Russia launched more than 500 drones and over 20 ballistic and cruise missiles overnight, targeting multiple regions across the country.

Zelenskyy said the Russian strikes wounded more than two dozen civilians, including three children.

A Russian overnight air strike also damaged port infrastructure in the Ukrainian city of Izmail on Tuesday.

"Fortunately, there were no casualties or significant destruction," local officials said on Telegram.