A Russian cargoship has crashed head-on into a South Korean bridge.

Video footage shows a vessel named by local media as the 9,700-dwt Seagrand (built 1986) hitting the Gwangan Bridge as it left the southeast port of Busan on Thursday.

Cars can be seeing slowing down as it becomes apparent that the ship will hit the bridge.

Some then cautiously drive on when it appears that the vessel has come off worse in the encounter.

A five-metre hole in the bridge was reported by Korean media.

The Yonhap news agency cited authorities as saying the ship had veered off course.

The country's coast guard said the Russian captain, whose identity is being withheld, had a blood alcohol content of 0.086%, against the legal limit of 0.03%.

It is not clear if he was on the bridge at the time.

The ship was bound for Vladivostok with steel coils onboard.

Authorities said the Seagrand had also hit a cruiseship moored in the port about 40 minutes before hitting the bridge.

The cargo vessel is listed as managed by Grand Marine Co of Vladivostok.