RIYADH (AFP) - Saudi Arabia has cut back the number of pilgrims that may perform the hajj this year due to construction work aimed at expanding the holy site of Mecca, the hajj minister said.

The authorities decided to reduce by half the number of pilgrims coming from within Saudi Arabia, and by about 20 per cent those from abroad, said Mr Bandar Hajjar. Some 3.1 million pilgrims performed the hajj last year, most of them from abroad.

"This is an exceptional and temporary decision," the minister said, quoted by SPA state news agency late on Saturday.

Mr Hajjar said the expansion of the Grand Mosque in Mecca would add 400,000 sq m, raising its capacity to accommodate 2.2 million people at the same time. The mosque houses the Kaaba - the cube-shaped structure towards which Muslims worldwide pray.

The decision comes also as Saudi Arabia battles the spread of the Sars-like Mers virus, which has killed 28 people in the kingdom since September out of 33 victims worldwide.

This year the hajj falls in October.