A five-year-old Palestinian boy has died in Gaza after suffering a severe panic attack during Israel’s air strikes on the strip, local media cited the health ministry as saying on Wednesday.

Tamim Dawood, who had been receiving treatment for a heart condition, was among the 20 civilians who were killed by Israeli raids, the reports said. At least 40 others were injured, according to reports.

The boy had been responding to his treatment well and was attending kindergarten prior to the panic attack, his mother told local media. When loud explosions erupted across the Gaza Strip on Tuesday evening, Dawood had a severe panic attack and was immediately rushed to a hospital.

“Tamim stayed in intensive care but was unresponsive. The doctors told us he died at dawn on Wednesday because his heart could not bear the fear,” his mother was quoted as saying.

Israel air strikes and raids have killed at least 125 Palestinians this year.