Ahmed el-Ansari, the emergency services chief, told The Associated Press the identities of the dead were not immediately clear. He said 28 people were injured, mostly with fractures, crush injuries and lost body parts, with some in critical condition. He said the scene had been cleared of victims.
The head of the Giza security sector, Kamal el-Dali, told the Nile News state TV station that most of the dead and injured were family members on a bus returning from a wedding in Cairo. El-Dali said the family had been heading to the southern city of Fayyoum.
El-Dali said the train, which carried construction materials, also hit a small truck coming from the opposite direction.
A security official said the train was traveling from the southern city of Beni Suef when it hit at least three vehicles near the village of Dahshur, about 40 kilometers (25 miles) south of Cairo. The official spoke on condition of anonymity because he was not authorized to brief reporters.
The head of Egypt's railway, Hussein Zakaria, told Nile News that initial reports indicated the crossing gates of the tracks had been closed and the train's driver was surprised to see vehicles still crossing.
"What could the guards have done? Stand in front of the bus?" Zakaria said. "The initial reports show no negligence ... We shall wait for the investigation."
Egypt is notorious for train collisions and has a poor safety record that is mostly blamed on decades of badly maintained equipment.
Almost exactly a year ago, a train crashed into a bus, killing 51 children traveling to school in the governorate of Assiut, some 200 miles (320 kilometers) south of Cairo. The transport minister and the head of the railways resigned following the accident.
That crash also gave ammunition to opponents of then-President Mohammed Morsi who said he had done little to improve lives of ordinary Egyptians. Morsi was ousted in a military coup in July.