Hamas operatives are afraid to enter underground tunnels in the Gaza Strip fearing they will collapse, The Jerusalem Post has learned from Palestinian sources.In addition, some of the operatives digging the tunnels believe Israel was involved in at least some of the recent tunnel collapses that claimed the lives of several Hamas men.The most recent collapse occurred on Thursday afternoon when a tunnel collapsed in Khan Yunis, killing one operative. The collapse marked the sixth such collapse in recent months – the highest number of collapses to have occurred since 2014’s Operation Protective Edge.Official reports, both in Israel and Gaza, describe collapses caused by recent storms and heavy rains. However, among Hamas and others, there are many who believe Israel is responsible.Hamas operatives have seen Israeli activities near the border fence against tunnels and fear they are connected to the tunnel collapses. Some of the activists have even spoken of the methods Israel is supposedly using to cause the collapses.One operative claimed Israel is using liquid explosives, while another operative expressed fears of Israel’s ability to cause localized earthquakes, which could also collapse the tunnels.Hamas has mentioned the IDF’s elite combat engineering corps unit, which has special anti-tunnel measures, and the Oketz canine unit, which sends trained dogs into the tunnels. Senior Hamas officials have paid condolence calls to those killed in the tunnel collapses, but have refused to give the bereaved families further information on the incidents.According to the mother of one of the victims, Hamas would only say the collapse was caused by the weather, but failed to elaborate and maintained secrecy.The leadership of Hamas apparently cannot prevent the collapse of the tunnels and recently, leader Ismail Haniyeh claimed Israeli technology had been discovered underground.