Marine Security Belt naval drills are held annually by Iran, China and Russia near the Gulf of Oman. The waters are strategically important for global trade and oil exports in particular.

Russian and Chinese warships arrived in waters off Iran on Monday for annual naval drills between the three countries.

The main phase of the drills, known as Marine Security Belt, will begin on Tuesday near the port city of Chabahar on the Gulf of Oman.

Iran’s semi-official Tasnim news agency said the drills aim to “strengthen security in the region, and expand multilateral cooperation between participating countries.”

The Gulf of Oman is strategically important for global trade. It leads to the narrow Strait of Hormuz, which is a key shipping route for oil.

What do we know about the drills?

Russia’s Defense Ministry said it was sending two corvettes and a tanker from the Pacific Fleet.

“During several days in the northern part of the Indian Ocean, the crews will work out the tasks of liberation of captured ships, search and rescue at sea as well as conduct artillery firing at sea and air targets,” the ministry said in a statement.

The Chinese Defense Ministry said on social media it would deploy “a destroyer and a supply ship.”

Meanwhile, Iran said it contributed 10 ships from both its navy and the Revolutionary Guard.