CAIRO, Apr 23 (Aswat Masriya)- Egyptian prosecution ordered on Saturday the detention of political activist Haitham Mohamdeen 15 days pending investigation on charges of joining a "terrorist group" and inciting protests.

Mohamdeen, who is a leading figure of the Revolutionary Socialists movement, is accused of belonging to a "terrorist group" which the prosecution did not name, inciting protests and possession of leaflets at his house.

The movement said that Mohamdeen was arrested on Friday at dawn.

The prosecution began investigating today 12 people on charges of inciting protests on Apr. 25. The defendants were arrested during security campaign last Thursday in downtown Cairo.

On Thursday, security forces arrested at least 40 people during a series of raids on downtown Cairo’s cafés four days ahead of Apr. 25 planned protests, a security source told Aswat Masriya on Friday.

The source added that most of those arrested were released later but 14 people are still being interrogated.

On Apr. 15, thousands of protesters gathered in front of the press syndicate under the slogan "Friday of the Land" to protest against an Egyptian-Saudi border demarcation agreement. 

The agreement, which is yet to be ratified by the parliament, stipulates that Egypt will hand control over two Red Sea islands, Tiran and Sanafir, to Saudi Arabia.

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