"This is not a terror attack," a Netanya police spokesman said. A resident close to the scene told Israel Radio he smelled a strong smell of gas.RELATED:Gas explosion kills elderly woman, collapses homePublic Security Minister Yitzhak Aharnovitch who arrived on the scene, told Israel Radio, "Our working assumption is that this was caused by a gas tank, although nothing is certain." He added, "There is a strong smell of gas. What's important now is to evacuate all the injured from the building. Searches are still underway...there are probably people on the upper floors that were not hurt but are trapped. It may take hours to get them out. The rescue services will go room by room to search for trapped people."Police arrested a Netanya resident who they suspect may have cut a gas line causing a leak that led to the explosion, Israel Radio reported. The man was detained by Police earlier on Thursday, and later released, after allegedly trying to steal gas pipes which are made of metal that can later be sold, according to the report. An additional report said the suspect may have cut the gas line intentionally as part of a feud between competing owners of businesses in the building. Police were also expected to investigate claims that Amisragas inspectors, who said the gas lines were properly functioning, were guilty of negligence, Israel Radio reported.The building houses some 150 families on its upper floors while the ground floor is made up of various businesses. Several of the businesses are owned by the Abutbul family, an alleged organized crime syndicate in Netanya, Israel Radio reported.MDA Paramedics said that three women and one man were killed in the blast. Two of the women were in their forties, one woman was in her twenties and the man was in his fifties.MDA paramedics attended to the wounded at the building, located in Netanya's Atzmaut Square. Firefighters were also disconnecting the building from gas pipes and the electricity grid.The injured were evacuated to the Laniado Medical Center in Netanya, Hillel Yaffe Hospital in Hadera and Meir Hospital in Kfar Saba by MDA paramedics. Three of the wounded were listed as moderately injured, and the rest were slightly hurt. All but ten of the injured were treated and released by Friday morning.All 150 of the apartments in the building were evacuated and remained off limits to residents. Rescue teams continued to search the debris surrounding the building for more injured people. Three people were still missing as of Friday morning. A number of buildings around Atzmaut Square sustained heavy damage as a result of the blast. Police said there was "widescale destruction" in the blast area. A number of passers-by were lightly injured.Police sealed off Atzmaut Square. Drivers were asked to keep away from the area.