An Egyptian journalist on Sunday appeared before a military court, accused of spreading lies about the army's campaign against militants in the Sinai Peninsula.

The court in the Suez canal city of Ismailiya adjourned Ahmed Abu Deraa's hearing to September 18.

Abu Deraa, who writes for the independent daily Al-Masry Al-Youm, was detained on September 4 in north Sinai over published reports that army raids had hit a mosque and houses and also injured civilians.

Authorities say they are targeting "terrorists" in the peninsula that borders the Palestinian Islamist-run Gaza Strip.

Media watchdog Reporters Without Borders and rights activists have condemned his detention.

But military spokesman Ahmed Ali justified the journalist's detention and military trial.

"Investigations showed that Mr Abu Deraa spread lies, saying that the Egyptian armed forces were attacking mosques, women and children. He deliberately spread false news," Ali told reporters.

"He also entered military zones."

Ali said the charges against Abu Deraa came under the jurisdiction of the military, and therefore required a military trial.

Several civil society groups have slammed the increasing number of military trials of civilians since the army ousted Islamist president Mohamed Morsi on July 3.