Masked gunmen have seized four members of the Palestinian Islamic group Hamas from a bus travelling to Cairo from the Gaza Strip, officials have said.
The bus carrying 50 passengers was ambushed close to the Rafah border crossing with Gaza on Wednesday night.
Hamas has called on Egypt to secure the members’ release.
Relations between the militant group and Egypt have been strained since Islamist President Mohammed Morsi was ousted from power two years ago.
Hamas is an offshoot of Mr Morsi’s Muslim Brotherhood – which is now banned in Egypt.
An Egyptian security official said four unknown men fired at the bus forcing it to stop.
The driver was assaulted and the Hamas members captured after their identity documents were checked.
The bus was being escorted by Egyptian soldiers at the time, according to Hamas.
“The graveness of such an incident was that it was the first of its kind and it breaks all diplomatic and security norms,” the group said in a statement.
The road from the Rafah border crossing runs through northern Sinai. The most active militant group in the area is an affiliate of the so-called Islamic State.
Egypt has previously accused Hamas of supporting militants in the Sinai desert, who seek to topple the Cairo government. Hamas has denied that allegation.
Israel, the US and several other nations have designated the group as a terrorist organisation over its long record of attacks on Israel and its refusal to renounce violence.