An Egyptian judge ordered on Thursday the 15-day detention pending investigation of 12 people for illegally protesting against the cabinet’s approval of the Egyptian-Saudi Red Sea island deal last week.

The defendants were arrested on Monday after gathering at the Journalists Syndicate in Cairo to protest the cabinet's approval of the deal despite the absence of a final court verdict on a lawsuit challenging the agreement.

The defendants are accused of illegal protesting, assaulting public officials, thuggery, illegal assembly, damaging public property and blocking traffic.

The cabinet approved the deal last week and referred it to parliament despite a June ruling by an administrative court halting the implementation of the deal.

A number of Egyptian political parties and coalitions have called for a protest on 11 January against the agreement in front of the cabinet's headquarters in Cairo. 

The parties which called for the protest include the Egyptian Popular Current, the Socialist Popular Alliance Party, the Egyptian Social Democratic Party, the Dostour Party, and the Karama Party.

The April 2016 border re-demarcation agreement between Cairo and Riyadh would place the Egyptian-controlled Red Sea islands of Tiran and Sanafir under Saudi Arabian sovereignty.

Egypt’s High Administrative Court has set 16 January 2017 to rule on the government’s appeal against the earlier June ruling.