Iranian media reported several explosions on the island of Kharg in the Gulf and near the port city of Jask on the Strait of Hormuz.
Explosions were heard on Tuesday evening in several parts of Kharg, including the port area, the government-aligned Mehr news agency reported. The Tasnim news agency reported a small oil tanker had been hit. The crew was abandoning the vessel.
There was initially no official information on the origin or cause of the explosions, according to the Mehr news agency.
Explosions were also heard near the port city of Jask in south-eastern Iran on the Strait of Hormuz, the Fars news agency reported. Iranian state broadcaster IRIB reported an oil tanker had been hit.
The reports could not be independently verified.
Several islands in the Gulf south of the Iranian mainland are of strategic and economic importance to the government in Tehran.
Kharg is Iran’s most important oil export terminal, with a large share of the country’s oil production shipped from the island. Because of its strategic importance, Kharg was repeatedly targeted during the Iran-Iraq War from 1980 to 1988.
The Strait of Hormuz is a key flashpoint in the war between Washington and Tehran.
Iran continues to largely obstruct shipping through the strait with threats and attacks on vessels. The waterway, which was open to shipping before the war, is of global importance for the transport of oil, natural gas and fertilizers.
The US is seeking to increase pressure on Tehran through a naval blockade of Iranian ports. The two sides have repeatedly exchanged fire in recent weeks.