Residents of Quorsaya island have blocked Al-Bahr Al-Azam Street in Giza after a military court postponed its verdict on 25 local people accused of attacking army personnel and property.
Clashes broke out in November when the army claimed rights to land on the island, which is near Maadi in south Cairo, and attempted to clear it of local residents.
Twenty-five people were arrested and transferred to a military prison.
The clashes killed one local resident.
North Cairo Military Court on Sunday postponed its ruling until 27 February.
The 'No to Military Trials' group on Monday organised a separate demonstration outside the court.
"Another month of unfair imprisonment for the people of Quorsaya for standing up for their rights," the group said via Twitter.
The army claims it has rights to 25 of 139 acres on the island for military training.
However, local residents won a court case in 2008 confirming their right to the land.
The dispute dates back to 2007 when the Mubarak government attempted to sell the land to businessmen for tourism development.