The navies of China, Iran, and Russia have begun joint drills in the Gulf of Oman, their fifth common military exercise in recent years.

According to The Iran Project,Russia’s defense ministry said the exercises that will run through Friday and involve warships and aviation would focus on the protection of “maritime economic activity,” Al Jazeera reported.

State media reported that a grouping of ships from Russia’s Pacific Fleet, led by the Varyag cruiser, arrived at the Iranian port of Chabahar on Monday ahead of the drills that will see representatives from the navies of Azerbaijan, India, Kazakhstan, Oman, Pakistan, and South Africa act as observers.

For its part, China’s defense ministry said the drills – called “Maritime Security Belt – 2024” – were aimed at “jointly maintaining regional maritime security”.

“China will send … guided-missile destroyer Urumqi, guided-missile frigate Linyi, and comprehensive supply ship Dongpinghu to participate in the exercise,” the ministry added in a statement, without providing further details.

Iranian media, meanwhile, reported that the exercise’s goal is to strengthen “the security of international maritime trade, combating piracy and maritime terrorism”, among others.