In Egypt, attacks on military and government sites kill 9 CAIRO - A trio of attacks against military, security and government-linked targets rattled Egypt on Monday, a day after violent street clashes on a military holiday left more than 50 people dead and at least 250 hurt. Monday's strikes, which killed nine people, prompted emergency precautions at Cairo's international airport, the semiofficial Ahram Online website reported. It said security was stepped up at airport entrances and exits, at the arrival and departure terminals, and on roads leading to the airport. There was no immediate claim of responsibility for any of the assaults, but the interim government remains locked in conflict with Islamist groups three months after the military stepped in amid a wave of demonstrations and deposed Islamist President Mohamed Morsi. In the deadliest of the three attacks, masked assailants opened fire on a military patrol near the Suez Canal city of Ismailia, killing five soldiers and an officer who were riding in an open truck, according to state media. It was the third such shooting in the area in recent days. Earlier, a powerful bomb went off outside a security headquarters in the Sinai Peninsula, killing at least three people and wounding dozens, the Interior Ministry said. Officials initially said the blast was caused by a car bomb but later blamed it on a suicide attacker. And in the most unusual of the strikes, a rocket-propelled grenade was fired before dawn at the main government-run communications installation in a normally tranquil Cairo suburb, according to official media. Although damage to the compound was reported as minor, affecting only one satellite dish, it could signal determination on the part of attackers to take aim at vulnerable civilian infrastructure. That concern appeared to have prompted the tightening of security at the airport. The Sinai blast, too, suggested a potential expansion of the scope of fighting in the rugged peninsula. The attack took place in the town of El Tor, in an area somewhat removed from the swath of northern Sinai where the military launched a major offensive against Islamist groups more than a month ago. It lies closer to the Red Sea tourist center of Sharm el Sheik, one of the very few parts of Egypt where a tourism free fall has been avoided. Morsi's followers in the Muslim Brotherhood, who flooded the streets Sunday during celebrations marking the anniversary of the 1973 war with Israel, have vowed to return to key sites Friday, the main Muslim day of prayer. On Monday, Egyptian authorities put the official death toll from Sunday's fighting at 53 and said most had been killed by live ammunition. In statements Monday, the resolve of both sides appeared to harden, setting the stage for a new round of violent confrontations. The government described anti-army protesters as foreign agents and terrorists and said they would be dealt with harshly, while the Brotherhood renewed demands for the reinstatement of Morsi, the country's first democratically elected president, and said it would continue to send its followers into the streets to challenge security forces.