A state security prosecutor in the United Arab Emirates says 30 Egyptian and UAE suspects have been charged with plotting a coup linked to a network of Egypt's Muslim Brotherhood, in a case likely to further strain relations with Cairo.

The move also deepens the UAE's crackdown on perceived threats since the Arab Spring, including 94 alleged backers of an Islamist group awaiting a July 2 verdict on charges of seeking to topple the Western-allied ruling system.

The official news agency WAM quotes prosecutor Rashid Ahmed al-Dhanhani as saying the suspects allegedly recruited members and raised money for the Brotherhood "seeking to seize power." Eleven of the Egyptian suspects were already in custody.

The UAE's pressure has opened serious rifts with the Muslim Brotherhood-led government of Egyptian President Mohammed Morsi.