Egyptian security officials say nine people, three Egyptians and six Israeli Arabs, have been referred to trial on charges they spied for Israel.

The officials say Judge Hisham el-Karmouty of the state security prosecution on Wednesday referred the nine to criminal court for allegedly passing on sensitive information to a foreign country on security centers in the Sinai Peninsula and about tunnels running under Egypt's border with the Gaza Strip.

The officials spoke on condition of anonymity because they were not authorized to brief the media.

Claims by Egyptian authorities of uncovering espionage rings run by Israel are not uncommon despite a 1979 peace treaty between the two Middle East neighbors.