Palestinian Hamas security guards stand near an Egyptian watch tower on the border with Egypt in Rafah, southern Gaza Strip, Friday, July 5, 2013. Egyptian official said the country’s border crossing with Gaza Strip in northern Sinai has been closed indefinitely, citing security concerns. The decision comes hours after suspected Islamic militants attacked four sites in northern Sinai, targeting two military checkpoints, a police station and el-Arish airport, where military aircraft are stationed. (AP Photo/Hatem Moussa)