One crude oil tanker, four liquified petroleum gas carriers, two oil and chemical tankers and one classified as an "oil products" vessel crossed the strait early Saturday after the Iranian announcement on Friday afternoon, data from tracking firm Kpler indicated.

Around a fifth of the world's oil and liquified natural gas pass the strait in peacetime but traffic through the route had come to a near-standstill after the war erupted on February 28 with US and Israeli strikes on Iran.

Tracking platform MarineTraffic showed several other crude oil tankers in the strait near Iran's Larak Island, a checkpoint for vessels seeking to exit the Gulf under Iranian forces' blockade of the passage in the war.

However, Iran's central military command on Saturday appeared to reverse the decision to reopen the route, saying it would resume "strict management" of the strait in protest at a US naval counter-blockade.

Iranian forces' closure of the strait has trapped hundreds of ships in the Gulf and driven up the costs of shipping goods, with captains avoiding the region for fear of attacks or mines.

At least three of the vessels tracked exiting via the strait on Saturday were listed as being under US sanctions. Some ships in the strait broadcast their identity as linked to India or China in a signal of neutrality.