An Egyptian policeman has been seriously wounded by Bedouin gunmen near the border with Israel, Egyptian security sources have said.
The shooting comes one day after hundreds of Bedouin from the Sinai peninsula gathered at the border.
They have asked for refuge in Israel saying the Egyptian authorities have mistreated their community.
Two Bedouin were killed on Wednesday after they failed to stop at a police checkpoint in central Sinai.
The Egyptian government has said that members of the Bedouin community have aided Islamist militants in carrying out bomb attacks on beach resorts in Sinai last year.
The Egyptian security forces have launched major operations in the area which international human rights groups have criticised as heavy-handed.