An Israeli military source confirmed Sunday night that the Egyptian military has deployed “additional ground forces” of an unspecified quantity to the northern Sinai Peninsula in an attempt to rein in Islamist extremists.

Cairo aims to launch a major ground offensive against Islamist terrorist groups that run rampant in the lawless territory bordering Israel and the Gaza Strip, an Egyptian military source told the Palestinian Ma’an News Agency. The Egyptian military has deployed six Apache helicopters to reinforce the ground troops, and additional infantry and naval craft have been dispatched to the Suez Canal zone in order to protect maritime traffic from terrorist attacks.

An IDF source confirmed the reports of Egyptian mobilization in the Sinai to The Times of Israel and said that “The Egyptian military activity in Sinai is coordinated with the Israeli military and authorized at the most senior Israeli levels, in order to address security concerns that pose a threat to both countries.” 

The communique came a few hours after Egypt Independent reported that unidentified gunmen had attacked Egypt’s Rafah border crossing in a brazen daylight raid. No injuries were reported and the Egyptian military denied that any attack took place.

According to the paper, Sunday’s attack on the Rafah post was the 38th since the Egyptian Revolution began on January 25, 2011.

The latest deployment comes close on the heels of Egypt’s mobilization of additional military and police forces, along with helicopters and rocket launchers, to the northern Sinai Peninsula in late May as part of a buildup in response to the kidnapping of security forces there.

This is the largest call-up of Egyptian forces in the Sinai since August, after Islamist gunmen attacked the Rafah crossing and killed 16 Egyptian soldiers, hijacked an armored personnel carrier, and broke through the Israeli frontier. The Egyptian military, with approval from Jerusalem, dispatched troops to track down and root out militants embedded in the Sinai’s mountainous terrain.

According to the 1978 Camp David Accords, which formed the backbone of the Israel-Egypt Peace Treaty, Egypt may station “no more than one division (mechanized or infantry) of Egyptian armed forces” more than 30 miles from the Suez Canal. Egypt executed previous deployments in the past year with Israel’s approval.

In a report published last week, the US State Department said that Egypt’s security agency “the National Security Sector, which replaced the State Security Investigations Service in 2011, has struggled to fully understand and effectively combat terrorist threats,” and has had few successes in the Sinai Peninsula.

Northern Sinai in particular, which includes Rafah and the intersection of the Israeli and Gaza Strip borders, “remained a transit route for smuggling arms and explosives into Gaza, as well as a base and transit point for Palestinian violent extremists. The smuggling of humans, weapons, cash, and other contraband through the Sinai into Israel and Gaza supported criminal networks with possible ties to terrorist groups in the region,” the State Department reported.