Egypt's interim President Adly Mansour has convened a high-level security meeting at the presidential palace in Cairo's Heliopolis district, informed sources told Al-Ahram's Arabic website.

Interim Prime Minister Hazem El-Beblawy has reportedly arrived at the palace to attend the talks, along with members of the National Security Council which is composed of civilian, security and army officials.

The meeting will address options for ending two sizeable sit-ins held by supporters of deposed president Mohamed Morsi after the government signalled an end of "diplomatic efforts" to resolve the ongoing stand-off with Morsi's Islamist supporters following his 3 July ouster.

Tensions have been running high in Egypt after cabinet and interior ministry officials said a crackdown on pro-Morsi protest camps was imminent, fuelling fears of a violent confrontation between security forces and Morsi supporters clamouring for Morsi's reinstatement.

Security issues expected to be addressed during the talks include militancy in the Sinai Peninsula, namely the ongoing operations by the Egyptian army to crack down on Islamist militants near Egypt's border with Israel and the Palestinian Gaza Strip.