CAIRO (Reuters) -A small bus in an airport which is used by the multinational observation force in Sinai exploded on Monday and initial reports indicated there were dead and injured, an Egyptian security source said.

&#34A microbus inside the airport exploded,&#34 the security official in North Sinai said. He said he did not know the reason for the blast.

The source said the blast occurred at an airport at El Gorah, a camp in the North of Sinai which is used by Multinational Force and Observers (MFO).

The MFO was set up to supervise the implementation of the security provisions of the Egyptian-Israeli peace treaty.

An MFO official had no immediate comment. Egypt”s Interior Ministry also had no immediate comment.

The North Camp at El Gorah, which is about 20 km (13 miles) south of Sinai”s Mediterranean coast, is the MFO”s largest installation and site of the force commander”s headquarters, the MFO”s Web site said.