For several terrifying days, air raid sirens have wailed nonstop in Kyiv, Ukraine’s capital, as waves upon waves of armed Russian drones surged into the city, straining its limited air defenses and exhausting a population worn down by years of war.

This latest stage of Russia’s air campaign has targeted warehouses and shopping centers, and on Saturday, the Ukrainian authorities said that a strike on a facility just outside Kyiv had killed at least 27 people.

The strike, which took place late Friday, caused huge secondary explosions that engulfed an entire suburban area in plumes of smoke. The Ukrainian authorities did not say what the facility was, but their comments suggested it was a warehouse with ammunition.

President Volodymyr Zelensky of Ukraine said on Saturday that a criminal investigation was already underway into the management of the warehouse, which is near private homes and a facility for older adults and people with disabilities.

An ammunition depot in another area outside Kyiv was destroyed last month, killing several people and prompting a separate investigation into the decision to store dangerous arms in civilian areas.

“Making the same mistakes for the fifth year of the full-scale invasion is criminal negligence,” Serhii Koretskyi, Ukraine’s prime minister, said on Saturday. “And all those responsible, without exception, must face severe punishment so that such situations do not happen again.”

Ukraine is struggling to counter the onslaught of Russian drones, many of which are powered by jet engines that allow them to fly at nearly 400 miles an hour.

The latest drone campaign has coincided with Ukraine’s dire shortage of Patriot interceptor missiles, the only weapon the country has that can shoot down ballistic missiles.

Russia has seized on that gap in Ukraine’s arsenal this summer. Civilians are bracing for the possibility that waves of Russian drones are intended to wear down air defense units before an even larger ballistic attack in the coming days.

In the past, Russia often launched daytime waves of reconnaissance drones ahead of combined drone and missile attacks overnight. But the droves of armed drones that now swarm the capital daily suggest that Russia is using a new tactic to spread fear and anxiety.

Most shops and restaurants remain open in Kyiv, but the constant attacks have caused major traffic jams and delays on the metro system. They could also significantly complicate plans for students to return to school on Tuesday.