Tsunami warnings begin as huge 7.4-magnitude earthquake rocks Papua New Guinea
A technician of the French National Seism Survey Institute (RENASS) presents a graph of an earthquake. [Agence France-Presse]

A 7.4 magnitude earthquake struck off Papua New Guinea on Tuesday with hazardous tsunami waves possible along the coast, seismologists said.

The quake struck 133 kilometres (83 miles) south-southwest of the town of Kokopo in the New Britain region at a depth of 63 kilometres, the US Geological Survey said.

The Pacific Tsunami Warning Center said "hazardous tsunami waves are possible for coasts located within 300 kilometres of the earthquake epicentre".