A bomb killed four people on a train in the Nile Delta on Wednesday, the head of the ambulance authority has told Ahram Online.
The bomb exploded in the last compartment of a train that had stopped at Menouf station in Menoufiya governorate.
Two of the victims were low ranking policemen, and another two were civilians.
The railway authority said the explosion took place when policemen were searching the train after passengers had reported a suspicious package.
Local health official Hanaa Sorour told state news agency MENA that nine people suffered minor injuries and one person was transferred to hospital.
Egypt has been hit by a wave of bomb attacks since the ouster of Islamist president Mohamed Morsi in July 2013.
Early on Thursday, a bomb exploded near the Qobba presidential palace in Cairo, injuring a woman.
*Correction: The article had previously stated five were killed in the bombing. This was incorrect.