South Korea ferry tragedy
Family members of passengers missing after the ferry Sewol capsized clash with police in Jindo during a protest calling for a meeting with President Park Geun-hyeReuters

The operator of the sunken South Korean passenger ferry Sewol has been involved in several controversial incidents in recent years, it has emerged.

The recent sinking, in which 50 people have been confirmed dead and more than 250 others are still missing, has brought the ship's operator, Chonghaejin Marine, into the spotlight.

The Yonhap news agency claimed that the vessel operator has reported maritime incidents at least once every two or three years. These incidents range from engine problems to collisions with other vessels.

Three weeks before the most recent disaster, one Chonghaejin Marine passenger vessel with 141 people on board rammed a fishing boat in the Yellow Sea. No casualties were reported.

In February 2013, a 6,322-tonne passenger ship belonging to Chonghaejin was delayed by several hours due to a generator glitch.

Meanwhile, relatives of the passengers of the sunken Sewol have expressed their outrage over the rescue operation.

Up to 100 distraught family members of the victims clashed with the police when they attempted to march to Seoul from Jindo island.

A bereaved woman shouted: "Bring me the body so that I can see the face and hug my child."

The 6,825-tonne ship, with 475 passengers, mostly students, was sailing in familiar waters from the mainland port of Incheon to the southern resort of Jeju when disaster struck.

Divers are continuing their operation to enter the submerged hull to retrieve bodies. So far they have pulled out 17 bodies and 253 remain unaccounted for amid little or no hope of survival.