KYIV, Ukraine (AP) — A series of loud explosions rang out in Ukraine’s capital early Monday followed by air raid sirens.

There was no immediate word on the origin of the explosions, but they sounded like air defense units firing into the sky.

Kyiv is routinely targeted by Russian drone and missile attacks.

Just over two weeks ago, Kyiv came under what Ukrainian officials said was the most intense drone attack since the beginning of Russia’s full-scale invasion in 2022.

Ukraine’s air force said Russia launched 75 Iranian-made Shahed drones against the capital, of which 74 were destroyed by air defenses.

The explosions Monday occurred just after 4 a.m. as the city was under its nightly curfew. There was no immediate information on any damage or casualties.