Global oil prices extended gains Monday amid a brewing diplomatic row in the Gulf region that has seen several states cut diplomatic ties with Qatar over its alleged support for extremists.

In a joint move that has escalated tensions in the region over Qatar's alleged support for the Muslim Brotherhood, Saudi Arabia, Bahrain, Egypt and the United Arab Emirates (UAE) said Monday that Qatari diplomats have 48 hours to return to Doha and have closed transport links to the small nation inside the Persian Gulf. Yemen declared a similar intent in a separate statement a few hours later.

West Texas Intermediate crude futures for July delivery were seen more than 1.2% higher at $48.15 while Brent contracts for the same month, were seen 1.25% higher at $50.37 each. Stocks on Qatar's benchmark also fell nearly 7% Monday with steep losses for shares in Qatar National Bank, the state's biggest lender, and Vodafone Qatar.

Qatar's Foreign Ministry said it regretted the moves by its Gulf Cooperation Council (GGC) allies and accused others of spreading misleading and inaccurate information with respect to its ties with Iran. "The campaign of incitement is based on lies that had reached the level of complete fabrications," the Ministry said.

The diplomatic spat marks the second time GGC states have pulled ambassadors from Doha and accused the government, which hosts the global news network Al Jazeera, of supporting terrorists and allowing them to spread messages through the media after a similar dispute in 2014.