Twenty-one Chinese navy vessels, headed to Pag-asa Island in the West Philippine Sea (WPS), have been spotted over the weekend, United States (US) Maritime Security Expert Ray Rowell said on Sunday.

In his Twitter post, Rowell said Philippine Coast Guard's (PCG) BRP Cabra monitored the Chinese militia on late evening of Saturday, August 12.

He said the 21 Chinese militia were among those that executed water cannons on PCG's vessels that were on a resupply mission near Ayungin Shoal in the disputed sea last August 5.

"China Coast Guard 4203, 5402 & 5304--all of which directly took part in last Saturday's blockade--have already returned to Hainan Island," Rowell added.

1/Late last night, 🇵🇭@coastguardph's BRP Cabra found itself in the midst of a redeployment of 21 🇨🇳PRC maritime militia ships headed NW toward Pag-Asa (Thitu) Island.
These 21 ships were among those swarming at Mischief Reef during the 🇵🇭's blockaded 5 Aug resupply. [🧵1/3] pic.twitter.com/xGcsKSHpiM

— Ray Powell (@GordianKnotRay) August 12, 2023

The American Maritime Security Expert said 19 CCG ships remained in the Automatic Identification System (AIS) dark.

Last Thursday, the Armed Forces of the Philippines (AFP) Western Command Commander Alberto Carlos revealed that they monitored nearly 500 ships in the WPS.

He said 85 percent of these ships were Chinese vessels.