Chinese officials have again denied using lasers directed at United States military pilots, a claim that first surfaced in Djibouti in April but has now reemerged in the South China Sea.

Some 20 incidents were recorded since September of last year, a U.S. military official tells CNN, with the most recent incident occurring in the past two weeks.

Pentagon spokeswoman Dana White previously said at least two people reported minor injuries, and the U.S. is confident the source is Chinese – but the Ministry of Foreign Affairs refuted that claim during a press briefing on Friday.

“The accusations against China made by the US media are groundless and sheer fabrications,” said spokesman Geng Shuang.

The U.S. first 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.

Four laser incidents occurred over 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 were expected to recover.

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. White House spokeswoman Sarah Sanders warned in May of “near-term and long-term consequences” for China when asked about developments in Djibouti and the South China Sea.

Image: China MFA