The Egyptian army struck terrorist camps in the Sinai over the course of Tuesday night, killing an estimated 20 terrorists. The strikes followed a large-scale attack near Gaza on Sunday, where terrorists attacked Egyptian army posts and then attempted to enter Israel, and a shooting attack late Tuesday night in Al-Arish.

The army used combat helicopters to hit the camps. The counter-terror assault is the first time the Egyptian army has used missiles in Sinai since attacking Israel in the 1973 Yom Kippur War.

Following the Sunday attack, in which 16 soldiers were killed, Egyptian President Mohammed Morsi and his top general warned that retaliation would be soon to come.

They also instructed soldiers to open fire on terrorists immediately in the future.

Head of Egyptian intelligence Mourad Mowafy said Tuesday that Egypt had received intelligence about the terrorist attack Sunday, but had not been expecting the assault. “Despite the detailed information about the attack, we never imagined that a Muslim would kill a Muslim during the meal to end the Ramadan fast day,” he told Turkish media.