A mysterious explosion which obliterated eight Gazan homes, damaged another 30 and injured over 50 people on Monday originated in a house used by Hamas to store weapons, The Media Line has learned.

The Deir Al-Balah refugee camp in the central Gaza Strip was rocked Monday by an explosion centered in an uninhabited house belonging to 'Alaa Al-Danaf, a field commander of the 'Izz A-din Al-Qassam Brigades, the military wing of Hamas

The 'Iz A-Din Al-Qassam Brigades blamed the explosion on Israel, claiming it was an assassination attempt on their field commanders.

But speaking on the condition of anonymity, camp residents told The Media Line that Hamas was using the house to store weapons. Neighbors said that in the past they had appealed to Hamas to cease their activities in the camp, but were quickly silenced.

The testimony confirms claims made by the Israeli army, which has denied any Israeli involvement in the explosion. An Israeli army spokesperson told The Media Line that the Israeli Air Force was not active in Deir Al-Balah at the time of the explosion.

"Usually when such explosions occur the armed groups in Gaza announce it's Israel's fault," Hamdi Shaqqura, deputy director for program affairs at the Gaza-based Palestinian Centre for Human Rights told The Media Line. "But our investigations often find that this is not the case."

Shaqurra said he believed that armed groups try to hide the existence of bombs in residential areas, because local residents "would not agree to live on a barrel of explosives."

The human rights group sent a team of field researchers and attorneys to collect testimony from victims and eye-witnesses following the explosion. Witnesses told the rights group they saw a red glow emanating from the house prior to the explosion.

12-year-old Isma'il Younis, a neighbor, told The Media Line he was home watching TV when a red ray appeared, followed by a huge explosion that rocked the house, cutting electricity and sending plumes of smoke into the air.

Another neighbor added that the moment of the explosion felt like an earthquake, making her unable to see her children due to the density of smoke and dust.

Early in the morning following the blast, eyewitnesses in Deir Al-Balah told The Media Line, six Hamas mini-vans arrived to collect debris from the site.

Witnesses also told the Palestinian Centre for Human Rights that they saw Hamas activists surround the house in question and collect shrapnel and bombs, removing any evidence of weapons from the scene.

The rights group concluded that the explosion emanated from within the house and occurred "for no apparent reason, similar to some incidents in the past." The group speculated that the cause of the explosion was faulty manufacturing or bad storage of bombs.

In February 2008 the Palestinian Centre for Human Rights reported that Ayman Fayed, a member of the Al-Quds Brigades, the armed wing of the Islamic Jihad movement, his wife, three of his children and three neighbors had all been killed in an explosion in Al-Bureij refugee camp, in the central Gaza Strip.

A report, released by the rights group at the time, concluded that the explosion was likely "an internal one", citing eye-witness accounts of smoke and fire rising from the house seconds before the explosion. The group warned armed militias in Gaza from stockpiling explosives in residential areas, which threatens civilian lives and is against international humanitarian law.

Justin Alexander, a Middle East analyst for the Economist Intelligence Unit, said that the lack of space in the Gaza Strip, coupled with Israel’s monitoring of open agricultural areas, accounts for armed factions’ operations within residential areas.

"There aren't many non-residential areas in Gaza," he told The Media Line.

The United Nations Fact Finding Mission led by Judge Richard Goldstone found that Palestinian armed groups in Gaza had launched rockets from within urban areas during its war with Israel, which ended in early 2009.