Abdullah's health problems have raised succession concerns in the world's biggest oil-exporting country [Reuters]

Saudi Arabia's ruler, King Abdullah bin Abdul Aziz, has undergone a successful back operation at King Abdulaziz Medical City in Riyadh, Saudi officials say.

The Saudi Royal Court's statement on Monday said Abdullah underwent a surgery on Sunday "to retighten the binding connector around the third vertebra in the lower back".

"The operation was successful," it stated.

Abdullah, believed to be 86 years old, was admitted on Sunday to a hospital after complaining of lower back pain.

He had travelled to New York in November 2010 for two surgeries after he was diagnosed with a blood clot on the spine and a herniated disc.

Abdullah became king in 2005. His health problems have raised concerns about who is going to succeed him in ruling the kingdom, the world's biggest oil exporter.

Source: Agencies