GUANGZHOU, May 5 -- More than 10 vessels from south China's Guangdong Province are joining efforts to rescue 11 missing crew after two ships collided near the waters of Hong Kong's Po Toi Island on Monday morning, local authorities said.

A Chinese mainland cargo ship sank after colliding with another cargo vessel at around 2:30 a.m. local time. Twelve crewmen fell into the sea and one of them, a 47-year-old mainland man, was later rescued by a passing fishing boat, according to the Hong Kong Maritime Department.

The Guangdong Provincial Maritime Search and Rescue Center launched an emergency response and sent three patrol and rescue ships as well a helicopter to assist with the rescue.

Another 12 vessels and two rescue helicopters are also joining the mission, according to the Ministry of Transport.

The Chinese ship, Zhong Xing 2, was carrying cement when it collided with the 300-meter Marshall Islands-registered container ship, MOL Motivator, which was leaving Hong Kong for Guangdong.