Following a series of four car bombings in Cairo last Friday, Islamist militants also shot down a helicopter over the weekend, indicating a trend in the growing strength of rebel military groups.

According to The New York Times, the attack on the Egyptian military helicopter with surface-to-air missiles, "validated longstanding fears that such weapons would spill into Egypt and beyond after the Libyan civil war tore open Col. Muammar el-Qaddafi’s fearsome arsenals." The group that carried out the attack in the Sinai Peninsula are called the Champions of Jerusalem and are apparently inspired by al-Qaeda.

The group released video supposedly showing the rocket being fired and colliding with the chopper.

The attack comes the same weekend as a celebration held by the military-backed Egyptian government to commemorate the third anniversary of the toppling of Egypt's government. More than 250 people were injured in protests over the weekend and 49 were killed. According to the government, 350 people were arrested nationwide.