Three people were killed and several others were injured in an accidental explosion Wednesday in Khan Younis in the southern Gaza Strip, Palestinian news portal Al Resalah reported.
The injured, between the ages of 20 and 30, were transferred to the European Hospital in Khan Younis in stable condition.
According to the Hamas-affiliated Al Resalah, the blast which killed the "martyrs" was caused by a fire that broke out in a house. However a spokesman for Hamas's Ministry of Health told the Bethlehem-based Ma'an News Agency that the circumstances behind the explosion were not clear.
Last month, a Hamas commander was killed in an "internal explosion" in Rafah.
According to Palestinian reports, nine other members of Hamas's al-Qassam brigades were injured in what was deemed a "work accident".
Hamas named 30-year-old Ibrahim Nagib al-Ghoul as the fatality from the blast.
Meanwhile, Israeli media reported that the blast had occurred during a training session on producing explosive devices.
Yasser Okbi contributed to this report.