Five people ordered to be detained for 15 days, and government orders seizure of assets of 500 Muslim Brotherhood members

Egypt's top prosecutor has ordered five people – including four journalists working for the satellite news broadcaster al-Jazeera English – to be held for 15 days on suspicion of joining a terrorist organisation and spreading false news harmful to state security.

The order from the prosecutor general, Hisham Barakat, accused the five of belonging to the Muslim Brotherhood, the group to which the ousted president Mohammed Morsi belongs. It alleges that they set up a media network with the aim of "tarnishing Egypt's image abroad and harming its political position".

The journalists were arrested late on Sunday at a five-star hotel in Cairo. The network has demanded they be released.

Also on Tuesday, Egypt's interim government ordered the seizure of assets of more than 500 Muslim Brotherhood and Islamist leaders, including Morsi, as part of an ever-tightening crackdown on the group.

Abdel-Azzem el-Ashri, a justice ministry spokesman, said a ministerial inventory committee had ordered the "movable and immovable properties" of 572 Muslim Brotherhood leaders to be seized. Another justice ministry official said leaders on the list included Morsi and his family, as well as provincial Brotherhood leaders and members of the General Guidance Bureau, the group's executive body.

A security official said the list also included female Muslim Brotherhood members such as Azza el-Garf, and the wife of the leader, Khairat el-Shater, and his daughter. He said other Islamist leaders included Assem Abdel-Maged, the head of Gamaa Islamiyah, which waged an anti-government insurgency in 1990s against Hosni Mubarak.

The two officials said the list included those indicted in cases of inciting violence and those who were under investigation or who could be investigated.

The order is part of a wider state crackdown on the Brotherhood, first banned by a court order in September and declared a terrorist organisation by the military-backed interim government last week. The group denies being involved in the attacks and continues to hold near-daily protests demanding the reinstatement of Morsi, who was toppled in a military coup on 3 July after millions rallied against him.