LONDON- Saudi Arabia has deployed thousands of troops from Egypt and Pakistan along its frontier with Iraq, amid fears of invasion by

the al-Qaeda splinter group that has declared a radical Islamic state across the border, reported a source today.

Saudi Arabia has been strengthening its border defences since the crisis in Iraq began. Panicked by the advance of the Islamic State of Iraq and al-Sham (ISIS), Riyadh has taken the drastic step of calling in military assistance from its close allies to shore up the porous 500-mile border, Gulf security sources said.

Saudi Arabia spent an estimated 35 billion sterling pounds on defence last year, Leapfrogging Britain as the world's fourth-largest military spender. This massive outlay highlights Riyadh's unease.