The US military has warned airmen to beware of laser attacks near China’s first overseas military base amid increasing signs of friction between the two armed forces in the Horn of Africa.

The military issued a Notice to Airmen, later reproduced on the US Federal Aviation Administration’s website, that there had been multiple events “involving a high-power laser” just 750 metres (2,400ft) from China’s base in Djibouti.

“Use extreme caution when transiting near this area,” the notice added.

Multiple intelligence sources reported that Chinese garrison in Djibouti is suspected of operating a high-power laser weapon to temporarily blind pilots at the base or on a ship offshore, according to a report in Jane’s Defence Weekly last month.

But Chinese military observers said the lasers might have been used to scare off birds near the airfield or disrupt possible spy drones, rather than targeting foreign pilots.

They also pointed out that China is a signatory to the Protocol on Blinding Laser Weapons, which bans the use of lasers that cause permanent blindness.

Marine marksmanship instructors from Special-Purpose Marine Air-Ground Task Force Africa with members of Djiboutian Groupe d'Intervention de la Gendarmerie Nationale, Aug. 30, 2012. Marine Corps via 1st Lt. Dominic Pitrone

“The Chinese and US bases in Djibouti are really close, so one could disturb the other if the two sides don’t have a proper communication mechanism,” said Zhou Chenming, a Beijing-based military analyst.

Zhou noted that China has already publicly demonstrated its use of laser weapons against drones at air exhibitions.

The Chinese military base in Djibouti is just a few miles northwest of Camp Lemonnier, the only permanent US military base in Africa and home to 4,000 US military personnel.

Camp Lemonnier was established after the 9/11 attacks, and is mainly used as a counterterrorism hub in the region. A 2013 Washington Post report said the Djibouti government had forced it to stop drone flights — which numbered up to 16 a day — from the base due to safety fears and relocate its unmanned spy aircraft to a more remote location.

As the US has increasingly eyes China as a strategic rival, the proximity of the two bases in Djibouti means the two sides will be involved in a “quiet contest” to gather information about each other, according to Ni Lexiong, a Shanghai-based military expert, although neither side “would announce this openly”.

Work began on the 36-hectare Chinese base in 2016, which was to be used a logistics hub to resupply vessels taking part in peacekeeping and humanitarian missions off the coasts of Yemen and Somalia. Weeks after the base opened at the start of August 1 the troops based there started live-fire drills.

Camp Lemonnier, a US military base in Djibouti, is strategically located between the Horn of Africa and the Arabian Peninsula. Google Maps

Djibouti sits in a vital strategic location, close to the Suez Canal, one of the world’s busiest shipping routes, and offers troops stationed there easy access to trouble spots such as Sudan, Somalia and Yemen and could provide a base for aerial missions over Iraq and Syria.

The government has been happy to provide facilities for other countries’ armed forces, and France, Spain and Japan all have opened facilities there.

In 2016 Japan announced that it would increase the size of its base following the announcement that China was planning to open its own facility there.

That year, a Japanese warship was reported by Chinese state media to have dispatched frogmen to collect information on Chinese vessels that had docked nearby before they were driven away by “strong lights” and verbal warnings.

The Japanese side denied the claims, saying the divers were checking their own ships.