The Houthis are a group from Yemen, the country just south of Saudi Arabia. On Monday they said they had attacked Saudi oil, airport and army sites. They named an oil company site at Yanbu, the Shaybah oilfield and the airport in Riyadh, the capital. Saudi leaders had not yet said whether this was true, and Reuters, a news agency, could not check it.
The claims are shaking the oil market. Brent crude is a price traders use for oil. On Tuesday it was about $110 a barrel. Oil also travels by sea. A firm called Kpler says about 8.5 million barrels a day flowed through the Gulf area last week. The week before, it was more than 20 million.
Leaders are trying to calm prices. President Trump signed an order that waives some sanctions and tariffs on Russian energy. Sanctions are punishments that limit trade. On Monday the order pushed oil down by more than $3, but buyers came back and the price ended almost where it began.