A Russian drone smashed into a home in Ukraine's northeastern Kharkiv region overnight, killing a father and his three small children and seriously wounding their mother who is 35 weeks pregnant, officials said Wednesday. The strike completely destroyed the house and set it on fire, with the family trapped under the rubble, according to the Kharkiv regional prosecutor's office.

The 34-year-old father and his three children - twin boys aged 2 and their 1-year-old sister - were killed, while rescue workers pulled the mother alive from the rubble, prosecutors said. She sustained blast injuries, a traumatic brain injury, burns and hearing loss, they said. During the almost four years since Russia invaded its neighbor, and despite a new push over the past year in U.S.-led peace efforts, Ukrainian civilians have endured constant aerial attacks.