At least 150 tankers, including crude and LNG vessels, dropped anchor in open Gulf waters beyond the Strait of Hormuz and dozens more were stationary on the other side of the chokepoint, shipping data showed on Sunday, after U.S. and Israeli strikes on Iran plunged the region into turmoil.

The tankers were clustered in open waters off the coasts of major Gulf oil producers, including Iraq and Saudi Arabia, as well as liquefied natural gas giant Qatar, according to Reuters estimates based on ship-tracking data from the MarineTraffic platform. Many of the vessels were stationary within exclusive economic zones (EEZ) of the key Gulf countries, including Kuwait and the United Arab Emirates, according to MarineTraffic data.

An EEZ extends up to 24 miles and beyond local territorial limits of 12 nautical miles.

Dozens of cargo ships were separately clustered across various EEZs, the data showed.

Some 20% of global oil, including from producers Saudi Arabia, the United Arab Emirates, Iraq, Kuwait and Iran, passes through Hormuz, along with large volumes of LNG from Qatar.

In addition, at least another 100 tankers were anchored outside of the strait, along the UAE and Omani coasts and anchorage points as well as dozens of cargo ships, according to the data.

Several tanker owners, oil majors and trading houses suspended crude oil, fuel and LNG shipments via the Strait of Hormuz after the attacks and Tehran said it had closed navigation, trading sources said on Saturday.

"At present, no such formal suspension (of traffic through the strait) has been communicated internationally by recognized maritime authorities," the U.S. Navy-led Joint Maritime Information Center said in a note on Saturday.

"Mariners should expect increased naval presence, enhanced force protection postures, potential VHF hailing, congestion near anchorage areas outside the Strait, and insurance market volatility."