Egyptian troops went on alert Wednesday in the town of Rafah bordering Gaza, fearing Hamas operative may attempt to forcibly breach the border again, a security official said. Egypt's Foreign Ministry warned Palestinians in Gaza that any attempts to "infringe upon the Egyptian borders will be met with a serious and firm position." In January, Hamas operatives frustrated over a tightened Israeli closure of Gaza blew holes in the border partition, allowing hundreds of thousands of Palestinians to stream into Egypt unchecked for ten days and stock up on food and other goods made scarce by the blockade. The security official said about a thousand troops near Gaza were put on alert after Egypt received intelligence that Hamas operatives were preparing to bulldoze the rebuilt border and blow up the main crossing gate with mines. He spoke on condition of anonymity because he was not authorized to speak to the media. On Tuesday, Hamas leader Khalil al-Haya described the situation in Gaza as "no longer bearable" and renewed threats to breach the border again. Hamas has ruled Gaza since it seized control from Palestinian Authority Mahmoud Abbas' Fatah forces in June. Israel sealed off Gaza after the Hamas takeover, causing shortages of fuel and other goods and increasing economic hardship for many of the 1.4 million residents of the impoverished strip. The Egyptian Foreign Ministry warned that any move to breach the border again would hurt the Palestinian cause and undermine efforts to end the Israeli embargo on Gaza. The ministry statement criticized the timing of the Hamas threats. It said they coincided with "the concocted problems inside Egypt," an apparent reference to this week's deadly riots over rising food prices. Police also reported discovering a large cache of explosives along the Egypt-Israeli border, 60 kilometers south of Rafah, a town divided by the Gaza-Egypt border. The large underground chamber showed signs of long-term use and contained 1,250 kilograms of explosives, 24 anti-tank mines and assault rifles. Police found the cache in a remote mountains Hadhira area with the aid of Bedouin trackers who are now scouring the area for suspects, the security official said.