CAIRO, Apr 24 (Aswat Masriya) - The now-banned Muslim Brotherhood group called on Egyptians on Sunday to participate in protests planned for Apr. 25 against an Egyptian-Saudi border demarcation agreement.

In a statement published on its official Facebook page, the group called on its supporters to "participate vigorously in the popular revolutionary movement on Apr. 25."

Calls for protest come in denunciation of an agreement signed between Egypt and Saudi earlier in April which stipulates that Egypt will hand control over two Red Sea islands, Tiran and Sanafir, to Saudi Arabia.

The two islands are strategically significant as they control the maritime activity in the Gulf of al-Aqaba.

The agreement has stirred controversy. Critics argue that the two islands are Egyptian, and accuse President Abdel Fattah al-Sisi of "selling Egypt" to Saudi Arabia in return for Saudi aid. 

President Sisi defended the agreement in a televised speech on Apr. 13, saying that "Egypt does not sell its land to anyone and it does not take anyone's land."

In protest to the agreement, thousands of people gathered in front of the press syndicate on Apr. 15 under the slogan "Friday of the Land" to underscore their objection to the agreement.

Protesters ended the demonstration then but said they will resume protesting on Apr. 25, which coincides with Sinai Liberation Day.

But days prior to Apr. 25, a security campaign was launched sweeping some  cafes in Downtown Cairo and resulting in the arrest of at least 40 people.

While most of those arrested were released later, at least 10 people remain in custody pending investigation, a security source said on Friday.

Interior Minister Magdy Abdel Ghaffar warned that security forces will respond with "utmost firmness" to any action that disturbs public security.

President Sisi was the country's defence minister when he led a military ouster of then-President Mohamed Mursi of the Muslim Brotherhood in July 2013 following mass protests against Mursi's rule.

Egypt listed the Brotherhood as a terrorist organisation in December 2013 and insists it is behind the wave of militancy which has targeted security personnel since Mursi's ouster.

The Brotherhood continuously denies the accusations and maintains that the group's demonstrations are "peaceful". 

The group had led a wave of protests calling for Mursi's reinstatement as president in 2013, but a once-vigorous wave of protests waned after a fierce by the Egyptian authorities.

The recently-signed Egyptian-Saudi maritime border agreement, which has yet to be ratified by the Egyptian parliament, has prompted protesters to return to the streets.