At least three Egyptian soldiers have been injured by sniper fire while guarding a security checkpoint in the restive northwestern Sinai Peninsula, Press TV reports.

Egyptian security sources said the troops were shot while guarding on a surveillance tower in the town of Sheikh Zuweid on Sunday afternoon.

The attack came hours after a powerful bomb explosion in the troubled peninsula left at least 18 soldiers wounded. The incident occurred on Sunday morning when a vehicle carrying the Egyptian troops hit a roadside bomb in the Kholafaa area of the city of el-Arish.

Also on Sunday, one woman was killed and her two children were injured in shelling by militants in the North Sinai border town of Rafah.

Militants also shot dead an Egyptian policeman in Sheikh Zuweid on Saturday.

Members of Egyptian security forces have been facing growing violence in the volatile Sinai Peninsula mainly from a local terrorist group known as the Velayat Sinai (Sinai Province). The Takfiri militant group has claimed responsibility for numerous deadly attacks on government targets.

In early July, a deadly assault on checkpoints killed at least 17 Egyptian military soldiers in north Sinai.

The Velayat Sinai militant group pledged allegiance to the Takfiri ISIL group in November 2014.

Egyptian security forces have reportedly killed over 1,000 militants in Sinai since tensions rose when former army chief and current President Abdel Fattah el-Sisi ousted Egypt’s first democratically-elected President Mohammed Morsi in a coup in July 2013.