UPDATE 2-Egypt Sinai peacekeepers deny they came under fire

AL-ARISH, Egypt, Aug 12 (Reuters) - Unidentified gunmen shot

at an Egyptian security checkpoint in the Sinai region, scene of

an army offensive against Islamist militants, early on Sunday,

Egyptian and international officials said.

But an official for the Sinai international peacekeeping

force, which helps maintain the peace accord between Israel and

Egypt, denied that its own troops had come under fire.

An Egyptian official had said gunmen opened fire on the

peacekeeping troops in the Um Shyhan area of central Sinai,

without causing any injuries, after shooting at a police

checkpoint and clashing with Egyptian security forces.

"We were not fired upon," said Kathleen Riley, Cairo

representative of the Multinational Force and Observers (MFO)

which has monitored movements of troops and military equipment

along Egypt's border with Israel since their 1979 peace treaty.

"There was some firing on an Egyptian army checkpoint or

police checkpoint not too far away. We were able to hear the

shots but we had absolutely no attacks upon our staff."

The incident follows the start of an Egyptian operation

targeting Islamist militants in Sinai suspected of killing 16

border guards a week ago.

The government in Cairo has sent armoured vehicles and

hundreds of troops in the biggest build-up in the treaty's

demilitarised zone since Egypt's 1973 war with Israel.

Israel has called upon Egypt to crack down on growing

lawlessness in the Sinai, which has become a hideout for jihadi

groups opposed to Israel.

Israeli officials say they approve of the Egyptian military

operation and the peacekeepers say they are continuing their

work in coordination with the two sides.

Armed assailants have attacked several checkpoints since

last Sunday's attack on the border guards.