One Palestinian was killed and 36 others injured Monday in an explosion in a house of a Hamas militant in Der el Balah refugee camp in central Gaza strip, a Palestinian medical officer said. Adham Abu Selmeya, a Hamas medical officer in Gaza said that the explosion was a result of an Israeli surface-to-surface rocket.

Senior Hamas militant Abu Anas el-Danaf survived, according to Hamas sources.

Meanwhile, Israeli Defense Force spokesman said that the Israeli army wasn't involved in any attack on any house in central Gaza Strip. The explosion is apparently a work accident.

Israel launched wide-scale "Cast Lead" offensive in Gaza in December 2008. The three-week fight, which Israel said it launched to halt rocket firing from the strip, claimed the lives of some 1, 400 Palestinians.