Two Russian missiles hit the eastern Ukrainian city of Pokrovsk within 30 to 40 minutes of each other, killing seven people, including an emergency worker who was responding to the first strike, officials said Tuesday.

The bombardment began at 7:15 p.m. local time on Monday (12.15 p.m. ET), a local military leader said, when a short-range ballistic missile hit what President Volodymyr Zelensky called an "ordinary residential building" in the eastern Ukrainian city.

First responders arrived on the scene to treat the wounded and dig people out from under the rubble, only to be targeted themselves.

At least 81 people, including seven first responders working for Ukraine's State Emergency Service and 31 police officers, were wounded, said Pavlo Kyrylenko, the head of Donetsk Regional Military Administration. The deputy head of the Emergency Service's Donetsk branch, Andrii Omelchenko, was killed, according to Ukraine's national police.

"All of them were there when they were needed, putting their efforts into rescuing people after the first incoming. They knew there were victims under the rubble -- so one had to react, dismantle, get them out and save them. And the enemy struck again," the national police said in a statement.

The second strike prompted authorities to suspend work to clear the rubble due to fear of another strike, despite the widespread damage.

One video Zelensky posted on social media showed a heavily damaged apartment block at sunset, with residents seemingly in shock trying to assess the damage. Another clip showed emergency officials working through the smoke-filled, hazy ruins after what seemed to be one of the missile attacks.

Authorities said the blast radius of the two strikes was "very large," shattering at least 2,000 windows across the city and damaging residences, shops, administrative buildings and a popular hotel. Photographs shared by Ukrainian officials showed the hotel with several floors completely missing.

Debris cleanup had resumed by Tuesday morning. Rescue operations near a damaged five-story residential building were also underway, the State Emergency Service said.

Russian forces have been accused of carrying out double-tap strikes in both Ukraine and Syria, in which troops conduct a first missile strike, wait, and then a fire a second projectile shortly after, allegedly targeting the emergency works responding to the initial attack.

A report last year from the Organization for Security and Cooperation in Europe (OSCE) accused Russia of carrying out a double-tap attack in Kharkiv as well as other "clear patterns" of violations of international humanitarian law.

Pokrovsk is located in Donetsk, an eastern Ukrainian region where fighting has been ongoing since 2014, when Russia began backing pro-Moscow separatists in the Donbas region. Donetsk was one of four territories President Vladimir Putin said Russia would annex last year in violation of international law.