Egyptian security forces killed 53 militants since the beginning of a massive security operation, mainly in restive northern Sinai Peninsula, the epicenter of a years-long Islamic insurgency, the armed forces said Thursday, AP reported.

Spokesman Col. Tamer el-Rifaai said that forces also arrested five militants and 680 others including “criminal elements” and people suspected of supporting militants. He spoke at a press conference in the presence of senior military and Interior Ministry officials.

El-Rifaai also said that forces found and destroyed hundreds of militant hideouts, targets and explosive devices.

The casualty figures couldn’t be independently verified as journalists and independent investigators are banned from accessing the turbulent Sinai region.

The massive security campaign that began on Friday covers north and central Sinai and parts of Egypt’s Nile Delta and the Western Desert, along the porous border with Libya which authorities contend that Islamic militants and smugglers use as their route into the country. The operation involves land, sea and air forces. Authorities are not saying how long the operation will last.