Crude oil prices climbed to two-year high earlier this week, rising to levels unseen on the markets since 2015, before receding slightly, Bloomberg reports.

Brent and WTI crudes are now trading over $64 and $57 per barrel, according to Bloomberg.

Higher prices have been spurred on by uncertainty in the Arabian Gulf.

The Houthi rebels successfully launched a missile against Riyadh from Yemen on Saturday. No one was hurt in the attack, but the Saudi Foreign Minister, Adel El Jubeir, blamed Iran for instigating the war in Yemen and declared that Saudi Arabia has the right to respond to “hostile actions,” according to Bloomberg.

Further roiling the markets, Saudi Arabia detained a number of businessmen and high-ranking officials over the weekend for alleged corruption, according to The National. One official said the arrests were “phase one” of a larger campaign, Bloomberg reports.