NEW DELHI: Expressing shock over the tragic loss of lives in an attack on an hospital in Gaza, Prime Minister Narendra Modi on Wednesday said civilian casualties in the ongoing conflict were a matter of serious concern and those involved should be held responsible.

According to media reports, Hamas group said a massive explosion at the al-Ahli hospital in Gaza killed hundreds of people Tuesday. Hamas attributed the blast to an Israeli air strike, but the Israeli military said it was not involved and the explosion was caused by a misfired Palestinian rocket.

"Deeply shocked at the tragic loss of lives at the Al Ahli Hospital in Gaza. Our heartfelt condolences to the families of the victims, and prayers for speedy recovery of those injured," Modi said on X.

"Civilian casualties in the ongoing conflict are a matter of serious and continuing concern. Those involved should be held responsible," the prime minister said.

Hostilities between Israel and Hamas began after armed Hamas militants based in the Gaza Strip launched an unprecedented attack on Israel by land, air, and sea on October 7. Since the start of hostilities, as many as 2,778 Palestinians have been killed.

Media reports have cited official Israeli sources as saying that at least 1,400 Israelis and foreign nationals have been killed in Israel.