Gaza City: An explosion in the Gaza Strip killed three Palestinians and wounded five on Wednesday, a medical official said, but the reason for the blast was unclear.

The three were already dead on their arrival at hospital, and all were in their 20s, Hamas’ health ministry spokesman Ashraf Al Qudra said.

The other five were in serious condition, he said.

Witnesses said the blast took place at a training camp belonging to Hamas’ armed wing the Ezz Al Deen Al Qassam Brigades east of the city of Khan Younis in the southern Gaza Strip.

A blast during a “training session in bomb-making” killed a Qassam Brigades member and injured six others last month in the southern town of Rafah, on the Egyptian border, the group said.