Egyptian security authorities recovered a Palestinian man who had fallen into a coma after being trapped Sunday for several hours inside a tunnel he was digging to smuggle goods between Egypt and Hamas-controlled Gaza. Imad Kharboush, head of the northern Sinai emergency unit, said Palestinian Abdul-Rahman Attiya Shalloub, 24, was in a deep coma and had been rushed to surgery at the El-Arish general hospital. His condition remains very critical. Earlier, an Egyptian security official said the tunnel collapsed and the man was killed while a Palestinian official said the man was simply overcome with fumes from the gasoline he was smuggling overnight. Both officials spoke on condition of anonymity because they were not authorized to talk to the media. The Egyptian official said the Palestinian was found in the tunnel some 10 meters (yards) inside Egyptian territory. Meanwhile, a high level of alert declared in central Israel was lowered late Sunday morning after four illegal Palestinian infiltrators were caught in a car in Bat Yam. The Palestinians were transferred to security forces for interrogation. Late Saturday night, two Fatah terror operatives were killed by the IDF in northern Gaza, Palestinian sources claimed. Rescue workers reported three explosions near the town of Jabaliya. They said the two men were trying to plant an explosive device near the security barrier. Military officials said the Palestinian report was being looked into. On Friday, IDF troops shot and killed two Palestinian gunmen during clashes in the Gaza Strip, and a Kassam rocket slammed into a kibbutz kindergarten moments after the children had left the playground. A Hamas man was killed and another was wounded during a firefight with soldiers from the Golani Brigade's Egoz reconnaissance unit near the Kissufim crossing in the central Gaza Strip. On Friday night, IDF surveillance teams spotted an armed Palestinian approaching the security fence in northern Gaza. Soldiers from the Givati Brigade's Rotem Battalion were alerted to the scene; the Fatah gunman threw a grenade at them, and the soldiers killed him. On Saturday night, the IDF bombed an Islamic Jihad cell in the northern Gaza Strip. Palestinians said that two gunmen were wounded. IDF sources said that despite the relative lull in violence on the Gaza front, terrorist groups were still trying - almost daily - to target IDF soldiers along the border fence, either by planting roadside bombs or by laying ambushes for shooting attacks. On Friday, three Kassam rocket struck the western Negev, including one that scored a direct hit on a kindergarten in a kibbutz in the Sha'ar Hanegev region, moments after the teacher whisked the children into a protected room. The teacher and a parent of one of the children suffered shock and the building was damaged. The two other Kassams hit open areas. Meanwhile Saturday, Hamas said it was developing a new rocket that would have a longer range than the Kassam. "It is no secret that Hamas is enhancing its military capabilities, including the development of new missiles. This is our right. We do not deny it and have no concerns," Abu Odediya, spokesman for Hamas's armed wing, Izzadin Kassam, was quoted as saying by London's pan-Arab Asharq al-Awsat newspaper. Abu Odediya denied Iran was involved in the development of the group's missiles. "Any development is being carried out in the Gaza Strip. We do not belong to any foreign body," he said. Defense officials confirmed reports over the weekend that Islamic Jihad was now manufacturing a rocket with a range of 20 kilometers and capable of carrying 10 kg. of explosives. Most Kassams carry 5 kg. of explosives. Defense officials said the new rockets were fired into Israel a few times in recent weeks and demonstrated the terrorist group's continual efforts to upgrade its capabilities.