The same Chinese maritime militia vessel has returned to the waters off Kota Island, which the Philippines holds in the West Philippine Sea. Authorities say it is the second appearance there in less than two weeks, this time after an 11-day gap. The National Task Force for the West Philippine Sea confirmed the sighting and warned China against repeated challenges to Philippine sovereignty. Chinese militia ships operate in loosely coordinated flotillas and have become a fixture around contested features in the South China Sea. Philippine agencies keep watch on the vessels and lodge protests whenever they edge into waters around Philippine-held territory. Kota Island sits among the Spratly features that Manila controls and Beijing claims in full. The return visit is being read as another probe of how Philippine authorities respond to presence near their holdings. Officials said they will continue monitoring the ship and documenting every appearance for use in diplomatic complaints.