By Anna Voitenko and Max Hunder
KYIV (Reuters) - Elena Mazur rushed to the blast site of a Russian drone attack in Kyiv on Monday when she received a phone call from her mother saying she was trapped under the wreckage of a residential building.
"Please find someone to help me urgently! I'm buried under the rubble," Mazur, 52, cited her mother as saying as Mazur later stood near a ruined building where rescuers were digging.
She was still looking for her mother.
"We asked, we were told someone was taken to hospital, it might have been her but we do not know. She is not picking up the phone," Mazur said.
Hours earlier, residents of several Ukrainian cities had scrambled for cover for the second time in a week as Russia launched attacks with drones and missiles, striking residential areas and energy infrastructure.
Four people, including a woman who was six months pregnant and her partner, were killed when a "kamikaze" drone hit a block of flats on the edge of Kyiv's central Shevchenkivskyi district, the city mayor said.
Explosions and gunfire echoed as security forces tried to shoot down the drones with automatic weapons. One elderly woman, hobbling with difficulty, was led to safety by a police officer.
Emergency workers rescued another old woman from the third floor of the residential building, the president's office said. It was unclear if she was Mazur's mother.
"Honestly, I have never been so afraid," said Vitaliy Dushevskiy, 29, a food courier who rents a flat in the building. "I'm still shaking."
"It is murder, it's simply murder, there are no other words for it. We are all so shaken, we do not even know what to do," he said.
Russia said it had hit military targets and energy infrastructure on Monday, but denies targeting civilians.
Dushevskiy's flatmate, Nazar, said they had tried to leave the flat after the blast and found there was no longer a staircase.
"Firemen came and they used a ladder to rescue us one by one. We then ran to the shelter in that building. It was horrible," he said.
Thick smoke billowed on to the street as firefighters picked through the rubble after the side of an apartment block collapsed. Rubble tumbled to the ground even as they dug.
'MISSILES ON MONDAYS'
The attacks came exactly a week after Russia launched its heaviest air strikes since the early days of its Feb. 24 invasion of Ukraine.
Some deaths were also reported outside the capital as Russia deployed more than 40 drones, most of which were taken out by Ukrainian air defences, the interior minister told reporters. He did not give a more precise casualty toll.
"This is already a tradition: to wake Ukrainians with missiles on Mondays," said Alla Voloshko, a 47-year-old lawyer who took shelter in the basement of her apartment block.
"I'm calm. I'm not scared... we will stay at home, we will stay in Kyiv as long as it’s possible,” she said.
President Volodymyr Zelenskiy accused Russia of terrorising civilians with kamikaze drones and missiles but said "Ukraine will prevail."
Ukraine's national grid operator said energy infrastructure in central and northern Ukrainian regions had been hit but that the power system remained under control.
In Kyiv, a Reuters reporter saw pieces of a drone that had been used in the attacks and bore the words: "For Belgorod."
The governor of the Russian region of Belgorod close to the border with Ukraine has accused Ukrainian forces of repeatedly shelling the region.
In other attacks, two drones hit the Everi marine terminal in Mykolaiv in southern Ukraine late on Sunday, damaging sunflower oil storage tanks, and setting ablaze leaking oil, said a senior manager who declined to give his last name.
It was the second attack on the storage facility on the Buh River since June, he said, describing the terminal as "an entirely civilian facility."