The international peacekeeping mission in the Sinai Peninsula confirmed that an Egyptian security checkpoint had come under fire early Sunday, but denied reports that peacekeepers were also targeted.

"We were not fired upon," said Kathleen Riley, Cairo representative of the Multinational Force and Observers (MFO) mission.

"There was some firing on an Egyptian army checkpoint or police checkpoint not too far away," Riley continued. "We were able to hear the shots but we had absolutely no attacks upon our staff."

The Reuters and dpa news agencies had previously reported that unidentified gunmen ambushed a camp of international peacekeepers in Sinai on Sunday.

"The attack happened in Um Shyhan area in the middle of Sinai but no one got injured," an Egyptian official had told Reuters.

The Multinational Force and Observers (MFO) mission is an independent organization that is tasked with monitoring the implementation of the Egypt-Israeli peace treaty.

Re-militarization of Sinai

Under the 1979 treaty, restrictions are placed on the deployment of military forces in Sinai as well as a zone in southern Israel. But Egypt has launched a military offensive in Sinai with the backing of Israel over the past week, in an attempt to root out suspected Islamist militants.

The offensive, the largest in Sinai since the 1973 Arab-Israeli war, was precipitated by attacks on Egyptian security checkpoints near the Israeli border a week ago last Sunday. Gunmen killed 16 border guards in those attacks.

Clashes have continued throughout the week. Cairo claims to have killed 20 suspected militants in a series of airstrikes and arrested several individuals. On Sunday, unknown gunmen again launched separate attacks on two checkpoints in the town of Sheikh Zuwaid near the border with Gaza.

The Sinai Peninsula has been characterized by growing lawlessness since the 2011 ouster of former Egyptian president Hosni Mubarak in a popular uprising.

slk/tj (Reuters, dpa)