Kickstarting tourism is one of the centrepieces of Crown Prince Mohammed bin Salman's Vision 2030 reform programme to prepare the biggest Arab economy for a post-oil era.

The announcement comes just two weeks after devastating attacks on Saudi Arabia's oil infrastructure –- blamed by Washington on Iran –- which roiled global energy markets and raised fears of a wider regional conflict.

"Opening Saudi Arabia to international tourists is a historic moment for our country," tourism chief Ahmed al-Khateeb said in a statement.

"Visitors will be surprised... by the treasures we have to share -- five UNESCO World Heritage Sites, a vibrant local culture and breathtaking natural beauty."

Saudi Arabia will open applications for online tourist visas to citizens of 49 countries on Saturday, Bloomberg News quoted Khateeb as saying.

Khateeb said the kingdom will also ease its strict dress code for foreign women, allowing them to go without the body-shrouding abaya robe that is still mandatory public wear for Saudi women.

Foreign women, however, will be required to wear "modest clothing", he added, without elaborating.

Visas in the desert kingdom, endowed with rich bedouin heritage and archaeological sites, are currently restricted to expat workers, their dependents and Muslim pilgrims travelling to holy sites in Mecca and Medina.

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