Ship-tracking data shows the number of vessels passing through the Strait of Hormuz increased on Tuesday, and most of them had traded with the Islamic Republic.

Reuters wrote that the move was carried out just before the U.S. maritime blockade began.

Data from the Kepler Institute indicates that of the 11 ships that passed through the strait on Tuesday, nine transited through the Islamic Republic’s route.

CNN also reported, citing the Windward Institute, that 23 ships of the Islamic Republic operate in the Strait of Hormuz with fake flags, by disabling receivers, or through other methods of concealment, and that seven supertankers carrying crude oil have been left idle on the waters of the Indian Ocean.

Traffic in the Strait of Hormuz remained sluggish on Wednesday, hours after the start of the U.S. maritime blockade on the shipping of the Islamic Republic, and only a small number of ships dared to pass.

According to Bloomberg, based on tracking data, a Greek Suezmax oil tanker carrying Saudi oil reappeared near Fujairah after three days of signal loss.