Iran’s military said an oil tanker caught fire in the Gulf of Oman while attempting to pass through a prohibited area, state television reported.

A military statement cited by the broadcaster said the vessel had switched off its tracking systems. The cause of the fire and who was responsible were not immediately clear.

The United States Central Command (CENTCOM), which is enforcing a blockade on Iranian ports, did not immediately comment. Iran’s Revolutionary Guards announced the boundaries of the zone in September.

Iran has declared the Strait of Hormuz closed since the outbreak of war with the United States in February. Disruption on the route can affect fuel supply and prices in import-dependent countries such as Sri Lanka.