SINAI, March 30 (Aswat Masriya) Four conscripts were wounded in an attack by armed assailants on a bus in Sinai's al-Sheikh Zuwaid on Sunday, security sources told Aswat Masriya. 

The assailants were in a vehicle hiding behind a building when they started shooting in the direction of the bus, eyewitnesses said, adding that the attackers escaped after the shooting. 

The wounded were taken to hospital for treatment while the authorities have begun combing the area searching for the perpetrators, the sources said. 

Attacks on security personnel have increased, especially in the Sinai Peninsula, since the ouster of President Mohamed Mursi of the Muslim Brotherhood last year. 

Egypt has in response stepped up security efforts, declaring a "war on terrorism".