Security has been stepped up at churches and cathedrals in Egypt as the country's interior ministry released the name and photographs of the Alexandria suicide bomber who struck on Palm Sunday.

Police searched passersby and cars around Orthodox cathedral of St Mark's Cathedral in Cairo, the seat of the Coptic Orthodox Pope, as beleagured Christians prepare for Easter Sunday.

There is a mood of 'fearful apprehension' after the Palm Sunday bombings in Tanta and Alexandria that left 45 people dead, AP reports.

The attack was just the latest in growing persecution of Christians in Egypt where the terror group Islamic State is defying President Abdel-Fattah el-Sissi and is active in underground cells.

'No security measure can stop a suicide bomber with jihadist beliefs from blowing up a church,' Coptic engineer Emad Thomas told AP. 'Egypt's Copts put their trust in God and not in security measures.'

Egypt's Interior Ministry named the suicide bomber as Mahmoud Hassan Mubarak Abdallah, a 30-year-old worker at a petroleum company. It also published the names of other members of the same cell, offering more than $5,000 for leads. 

The ministry Facebook page posted a photograph of the terrorist and stated he had worked for one of the oil companies. They identified him from his DNA and said Christian churches were being deliberately targeted.

In their investigations already, police have seized explosive belts and explosive devices and various types of weapons and quantities of ammunition and some terror manuals.