An overnight explosion in the Israeli coastal town of Netanya which left four dead, was caused by a gas leak and was not related to any criminal or nationalist issues, police said on Friday. The blast occurred late on Thursday in centre of the seaside town, flattening a four-storey building and injuring around 65 people, many of whom were sitting in a restaurant on the ground floor. \"The explosion was apparently caused by negligence,\" police spokesman Micky Rosenfeld told AFP, saying the dead included three women and a man, while the injured numbered at least 65. He was not immediately able to confirm media reports which suggested many of the injured were French tourists. \"The results of the investigation into the blast show it was not caused by an attack or through criminal gang-related activity,\" Rosenfeld said, pointing to a faulty gas canister. In the past, Netanya has been the location where figures from the criminal underworld have been known to settle scores. Rosenfeld said that a scrap metal dealer had been arrested in connection with the incident, and an employee of the gas company which supplied the cannisters was also being questioned. Investigators said the gas worker had come to examine the pipes around the building several hours before the explosion, following complaints from local residents but had found nothing amiss. The blast flattened the entire building, leaving people buried under the rubble, with cranes brought in to try to get them out, witnesses told Israeli radio. At least one witness said there was a strong smell of gas hanging over the debris.