Three soldiers were injured on Wednesday when unknown assailants opened fire at a military train in central Egypt's Beni Suef governorate, Al-Ahram Arabic news website reported.

First Assistant Ahmed Rizq, 40, Sergeant Mohamed Saeed, 25, and conscript Mahmoud Mohamed, 21, were transferred to hospital with shotgun injuries.

The train was attacked near Bani Hadir village.  

Police are investigating the incident.

Earlier on Wednesday, a policeman was shot dead by unknown assailants in the Nile Delta governorate of Menoufiya.

Anti-government Islamist militants have long targeted police and army personnel and sites, mainly in the Sinai Peninsula, but attacks have expanded to other parts of Egypt since the ouster of Islamist president Mohamed Morsi in 2013.

The government has launched an "anti-terrorism" campaign and announced the killing and arrest of hundreds of terror suspects.