SAN DIEGO (FOX 5/KUSI) -- Age-progression images of two brothers who were reportedly abducted by their father from San Diego six years ago were released Thursday by the National Center for Missing & Exploited Children. The images of 10-year-old Binyu Chin and his 13-year-old brother Huaiyu were created by a forensic artist to show what they would look like in the present day. According to NCMEC, the boys' mother Hongying Liu first met their father, Foong Chin, in New York while he was attending Columbia University. Beware of parking enforcement phishing scam: City of San Diego In 2004, Chin received a job offer in San Diego, leading them to move to the West Coast. The couple then started divorce proceedings in 2014 and had shared custody of their two sons, NCMEC said. On Jan. 12, 2019, Liu and the boys' stepfather called police after the older son did not show up for school and Chin did not return the younger son as scheduled following a weekend visit. Authorities discovered Chin's apartment had been emptied when they arrived, according to NCMEC. The search for the boys and their father is ongoing. Chin, 47, is wanted by the U.S. Marshals Service on charges of parental child abduction. Authorities said he has ties to New York, Southern California, Baja California, Mexico and Singapore. Anyone with information about Chin and his sons Huaiyu and Binyu is asked to contact the NCMEC at 1-800-THE-LOST or the U.S. Marshals Service of California at 1-858-565-5200.