Oil prices tumbled more after Iran struck US military base in Qatar, a sign Strait of Hormuz would stay open for now.

Oil prices hit a five-month high over the weekend after the United States struck Iran’s nuclear facilities. Tehran retaliated with an attack on the US Al Udeid Air Base in Qatar, keeping global energy markets on edge.

But oil prices dropped sharply on Tuesday after it appeared that Iran was holding off further attacks for now, including avoiding closing the Strait of Hormuz, a critical chokepoint in global trade.

Brent Crude, the international benchmark for oil prices, has tumbled more than 5.6 percent so far in the trading day and is currently trading at around $66 a barrel.

One of Iran’s most significant potential retaliatory economic measures would be to shut down the Strait of Hormuz.