General cargo ships Xin Dong Yuan and An Da Sheng collided near Pingtan, Fujian in China on Saturday.
The incident led to the sinking of Xin Dong Yuan sending all 13 crew members onboard the vessel into the water.
Fujian Maritime Rescue Center deployed rescue vessels and helicopters, and also coordinated nearby vessels for search and rescue operations. Four crew have been rescued and three have been found dead, while another six remain missing.
Xin Dong Yuan is operated by Wuhan Chenguang Shipping and An Da Sheng is operated by Cangzhou Bohai Anda Shipping.
Fujian Maritime Rescue Centre has also deployed an oil spill response team to the wreckage site to clean up a minor oil spill from the incident.