Authorities in the United States have filed a formal complaint with China over the reported use of lasers directed at U.S. pilots in Djibouti, where both countries have military bases near each other.

Four laser incidents occurred over the last several weeks at Djibouti, U.S. military officials said. Three involved a military-grade laser that appeared to come from the Chinese base, while a separate incident came from a different laser and location.

Two U.S. military personnel received minor eye injuries after they were hit by a high-powered beam while piloting a C-130 aircraft. The Wall Street Journal said the pilots became dizzy and saw “rings” after the incident but are expected to recover.

Intelligence analysts with Stratfor noted that the laser use may not have been intended to harm U.S. service members but was meant to disable sensors on aircraft to prevent surveillance on Chinese facilities.

There’s been speculation about laser use in Djibouti in recent weeks after U.S. aviation officials issued a warning for pilots on April 14 and asked them to report any incidents.

“Use caution for unauthorized laser activity,” the message said. “There have been multiple lazing events involving a high power laser in the vicinity.”

U.S. officials have demonstrated increasing concern over China’s presence on the African continent, especially the strategic Horn of Africa base in Djibouti that opened last year. China’s Ministry of Foreign Affairs dismissed those concerns in March and said the U.S. concern over port and infrastructure investment was misguided.

China’s MFA did not immediately issue a public statement on this latest accusation.White House spokeswoman Sarah Sanders warned of “near-term and long-term consequences” for China when asked about developments in Djibouti and the South China Sea during a routine press briefing.

Image: Ministry of National Defense/PRC file