Palestinian media reports claimed an Israel air force jet fired a missile at the house; however, the Israeli army said there were no activities in the Gaza Strip at the time of the blast.
An Israeli security official told Israel Radio the explosion may have been the result of a work accident, that a bomb being prepared blew up prematurely.
The force of the blast demolished the home of the Hamas commander identified as Alaa al-Danaf, and five other surrounding buildings in Dir al-Ballah in central Gaza, the Maan news agency said.
Danaf a senior member of the Hamas military wing is also a bomb expert, Palestinian media reports said.
Adham Abu Salmiyya, a medical service worker, told the news agency a missile was fired from an Israeli Air Force jet and hit the home.