The first world chess tournament to be hosted by Saudi Arabia has been mired in controversy after Israeli competitors were barred and Qatari players withdrew after being told not to show their country's flag.

The King Salman World Rapid and Blitz Chess Championships, which runs until Saturday, includes around 240 players - both men and women - from 70 countries. There are 16 players from Saudi Arabia.

It comes almost two years after Saudi Arabia's top cleric said chess was un-Islamic, and has been billed as part of Crown Prince Mohammed bin Salman's push for greater social reforms, including lifting a ban on women driving that goes into effect next year, allowing concerts and movies, and easing rules on gender segregation.

But the event was almost immediately mired in controversy after Israeli competitors were not granted visas.

Qatar's chess federation said its players had been granted visa but would not take part because organizers demanded that the players not display the Qatari flag during the competition.

Saudi Arabia has imposed an effective economic blockage against Qatar amid a confrontation over its funding of extremist groups and perceived Iranian influence in the island state.

A statement issued by the World Chess Federation said that visas for players from Qatar and Iran, which is also locked in a confrontation with Saudi Arabia, were secured. It made no mention of Israeli players.