CAIRO, Aug 22 (Reuters) - Egypt is to close the Rafah crossing on its border with the Gaza Strip until further notice on Monday, Egyptian security sources said. Hamas, the Palestinian faction that controls Gaza, said it had been informed by Egypt of the decision to shut the crossing in both directions, without giving details. According to two Egyptian security sources, the closure was made for security reasons following an escalation on Saturday between Israel and Hamas, with Israeli aircraft striking sites in Gaza after gunfire across Gaza"s border with Israel earlier in the day. read more Rafah is the sole crossing between Egypt and Gaza, where an Israeli-led blockade has placed severe restrictions on the movement of goods and people for years. Egypt had opened the crossing indefinitely in February in what was described as an effort to encourage negotiations between Palestinian factions meeting at the time in Cairo. Egypt kept the crossing open during and after an 11-day conflict between Israel and Hamas in May, delivering aid and construction materials through Rafah after helping broker a truce between the two sides.