U.S. military pilots have been repeatedly targeted with troublesome-yet-nonlethal lasers in the East China Sea in recent months, U.S. defense officials told The Daily Caller News Foundation Thursday, confirming several earlier reports.

More than 20 incidents have been reported since September 2017, with the most recent occurring within the past few weeks. These incidents follow alarming reports of Chinese military personnel harassing U.S. pilots with military-grade and commercial lasers in the small East African country of Djibouti, where China has a military base located just down the road from a strategically significant U.S. base.

The East China Sea incidents were reportedly carried out “from a range of different sources both ashore and from fishing vessels,” Indo-Pacific Command explained to Aviation Week. The East China Sea is a global hotspot where Chinese civilian and military vessels regularly operate. While defense officials revealed that some reported laser dazzling incidents involved Chinese-flagged fishing vessels, there is uncertainty concerning whether or not Chinese nationals were behind all of the laser-involved events.

Unlike the serious incidents in Djibouti, there have been no reported injuries in the East China Sea. U.S. defense officials, in conversations with TheDCNF, characterized the incidents as “an annoyance,” stressing that these incidents were not attacks, as they involved commercial laser pointers. Nonetheless, such devices could still temporarily blind a pilot or damage the eye, The Wall Street Journal explained.

The primary concern in Djibouti was the use of military-grade lasers, the use of which is prohibited by international law.

A Notice to Airmen (NOTAM) sent out on April 14 called attention to the occurrence of “multiple lazing events involving a high-power laser in the vicinity of N1135.70 E04303.14,” coordinates located near a new Chinese military base in Djibouti.

“Use extreme caution when transiting near this area,” the notice warned. (RELATED: China Has Reportedly Been Trying To Blind American Military Pilots With High-Powered Lasers)

The Pentagon blamed China, accusing Beijing of endangering American pilots.

“We have already refuted the untrue criticisms via official channels,” the Chinese Ministry of National Defense stated in response. “The Chinese side consistently strictly abides by international law and laws of the local country, and is committed to protecting regional security and stability.”

The U.S. is apparently not yet convinced the Chinese military is behind the incidents in the East China Sea. The incidents in this region are less serious than those seen in Djibouti, where pilots actually experienced eye injuries, but they are still disconcerting.

“A source from China’s Ministry of National Defense has dismissed a U.S. claim that China struck U.S. Forces with laser in the East China Sea,” the nationalist Global Times, a Chinese tabloid known for its provocative commentaries, wrote Thursday. “The claim is groundless and fabricated.”

Follow Ryan on Twitter

Send tips to ryan@ dailycallernewsfoundation.org.

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact licensing@dailycallernewsfoundation.org.