Ship traffic in the Strait of Hormuz slowed at the start of this week after the Islamic Republic warned on Monday that it would respond to any new U.S. attack.

Based on data from the firm Kpler, the number of cargo vessels that transited the strait on Monday was seven.

Tehran had warned that energy infrastructure across the Persian Gulf, including U.S. oil and gas interests, is vulnerable.

Traffic in the Bab el-Mandeb Strait, however, increased, rising from 17 vessels on Sunday to 29 vessels on Monday.

Many vessels pass through the Strait of Hormuz with transponders turned off and with U.S. Army support, which is not counted in the figures.