A delegation of Israeli security officials visited Cairo to discuss the security situation in the region with their Egyptian counterparts on Sunday, the second such trip in less than a week.

The Israeli group arrived on a special flight and were met at the airport by high-ranking officials from Egypt’s intelligence establishment, Israel Radio reported. No information regarding the identity of the Israelis was provided.

Jerusalem has a particular interest in security in the Sinai, which shares a long border with Israel and has been the source of a number of attacks on Israelis near the border in the past several years. The demilitarized peninsula has been described as a wild area where Jihadist groups operate under the radar of Egypt’s security forces, despite a crackdown on terror groups in the region last year.

On Sunday, the Egyptian army said officers had uncovered hundreds of smuggling tunnels running between the Sinai and the Gaza Strip, and expected there were hundreds more waiting to be found.

The army said it is working to close down and destroy the tunnels, many of which are used to smuggle weapons to Gaza, which is controlled by Hamas, considered a terror group by Israel and the US.

The tunnels are also used to sneak food and other goods into the Strip.

“Each tunnel has several exits, including inside Egyptian houses, and thus can be difficult to detect,” Colonel Ahmed Mohamed Ali told the Palestinian Ma’an news agency, noting that at least 225 of the smuggling routes have been found. He estimated there may be as many as 500 tunnels in toto.

Last week Egyptian forces pumped water into a number of tunnels and destroyed them, and stepped up efforts to detect more tunnels under its border with Gaza.

Tunnel owners in Rafah told the Safa news agency that over the past 10 days, Egyptian soldiers have set up checkpoints in Sinai, stopped incoming trucks and confiscated merchandise.

Last Thursday, an Israeli delegation of defense officials visited Cairo. Initial reports said they met with their Egyptian counterparts and discussed regional security issues, including terrorist activities in the Sinai Peninsula and the Israeli-Palestinian peace process. According to Egypt’s al-Masry al-Youm, the representatives arrived in Cairo in a military aircraft that waited for them on the runway. The group reportedly numbered four Israeli officials.

In fact, according to Israel’s Channel 10, these meetings were the latest in several weeks of talks in which the Israeli officials have been negotiating indirectly with Hamas, on issues including the reopening of the Rafah Border Crossing with the Hamas-controlled Gaza Strip to construction materials and basic commodities such as gasoline. The Egyptian defense officials have served as the intermediaries in the contacts.

The Israeli and Hamas officials are reportedly also indirectly negotiating the opening of Israeli border crossings for the export of Palestinian agricultural produce, and possibly a resolution of the issue of Palestinian security detainees in Israeli prisons.

Israel established a naval blockade of the Gaza Strip in 2007 in order to prevent arms-smuggling into the enclave. Hamas violently removed its Fatah rivals from the Strip when it seized power there that year, killing many of them in the process.

According to the agreement that ended Israel’s eight-day air campaign against terrorist groups in the Gaza Strip in November, “opening the crossings and facilitating the movement of people and transfer of goods” was to be dealt with after the initial cessation of hostilities.

Israel in December started allowing long-banned building materials into the Gaza Strip, one of the concessions to Hamas under the agreement.

Ron Friedman and Elhanan Miller contributed to this report.