ISMAILIA, Egypt Aug 20 (Reuters) - Egypt is preparing to use aircraft and tanks in Sinai for the first time since the 1973 war with Israel in its offensive against militants in the border area, security sources said on Monday.
The plans to step up the operation were being finalised by Egypt's newly appointed Defence Minister General Abdel Fattah al-Sisi as he made his first visit to Sinai on Monday following the killing of 16 border guards on Aug.5.
Egypt blamed the attack on Islamist militants and the conflict is an early test for President Mohamed Mursi - elected in June following the overthrow last year of Hosni Mubarak - to prove he can rein in militants on the border with Israel.
"Al-Sisi will supervise the putting together of final plans to strike terrorist elements using aircraft and mobile rocket launchers for the first time since the beginning of the operation," an Egyptian security source said.
Another security source said the army was planning to attack and besiege al-Halal mountain in central Sinai, using weapons including tanks, where militants were suspected to be hiding.
Disorder has spread in North Sinai, a region with many guns that has felt neglected by the central government, since the overthrow of Mubarak in a popular uprising. Mubarak's government had worked closely with Israel to keep the region under control and Islamist President Mursi has promised to restore stability.
The 1979 peace treaty between both countries limited military presence in the desert peninsula though in recent years Israel agreed to allow Egypt to deploy more forces there to stem weapons smuggling by Palestinian gunmen and other crimes.
After the border attack this month, Egypt launched a joint army-police operation that has raided militant hideouts, arrested their members and seized weapons.
Israeli officials, who say they are in regular contact with Cairo, have encouraged Egypt to take tough action against the gunmen responsible for the assault and have previously allowed the use of helicopters in the operation.
No one has claimed responsibility for the killing of the border guards but a Sinai-based Islamist militant organisation, the Salafi Jihadi Group, warned the Egyptian army last week that the crackdown would force it to fight back.
Al-Sisi was appointed defence minister last week in a surprise shake-up by Mursi, replacing Field Marshal Hussein Tantawi who served as Mubarak's defence minister for 20 years.