Qatar's Prime Minister Sheikh Abdullah bin Nasser al-Thani will attend an Arab summit in Saudi Arabia to discuss regional security, Al Jazeera reported on Wednesday, the highest level Qatari official to visit the kingdom during a diplomatic rift. The emergency summit at Mecca, Islam's holiest city, will on Thursday discuss tensions with Iran following attacks on oil tankers off the coast of the United Arab Emirates and drone strikes on oil pumping stations in Saudi Arabia, both of which Tehran denies involvement in.