CAIRO, Feb 9 (Reuters) - Twenty-six alleged Islamist militants, including two former military officers, will stand trial on terrorism charges, accused of planning attacks against the Egyptian state, the official news agency MENA said on Saturday.

The state security prosecutor said they had formed an extremist organisation that advocated sedition against public authorities and called for jihad against public servants employed at state institutions.

"Investigation by national security revealed the defendants planned to carry out terrorist attacks inside Egypt during Eid al Adha," MENA reported, referring to the Muslim festival which falls in October.

"As a result, security officials raided their cells simultaneously," it said. The suspects, who included one Tunisian, were also charged with possession of weapons and explosives.

MENA said Taha Abdel Salam, one of the two former officers, was accused of being a important recruiter for the group, and had been suspended from the army in 2002 for having links to militants.

Two years after the revolution that toppled president Hosni Mubarak, Egypt's Islamist rulers are contending with a rise in militant activity, especially in the Sinai region that borders Israel and the Gaza Strip, while struggling to contain street protests that have frequently turned violent.

Domestic turmoil and the smuggling of weapons from Libya after the fall of dictator Muammar Gaddafi have created a security gap. In August, 16 Egyptian border guards were killed in Islamist militant attacks in Sinai.

MENA said the defendants in the latest case belonged to suspected cells based in Cairo suburbs, and lived in rented apartments under false names. In October, one suspect was killed when he opened fire on security forces raiding militant cells in the suburb of Nasser City. (Writing by Marwa Awad; Editing by Mark Trevelyan)