An earthquake has struck off the coast of Papua New Guinea, it has been reported. 

It was measured at a magnitude of 6.9 on the Richter scale. 

The Pacific Tsunami Warning Centre (PTWC) issued a warning and forecast hazardous waves from the coast. 

“Government agencies responsible for threatened coastal areas should take action to inform and instruct any coastal populations at risk,” the PTWC said in its alert.

“Persons located in threatened coastal areas should stay alert for information.”

The quake, which was very shallow below the seabed and close to the coast, struck at 07:25 am on Friday (21:25 GMT on Thursday) and was centred 100 miles southwest of Rabaul, a township in East New Britain province.

Australian authorities said there was no threat to their coastline from the quake, which was initially reported as a magnitude 7.2.

Papua New Guinea lies within the complex zone of collision between the Australian Plate and the Pacific Plate.

It is one of the world’s poorest countries and is still reeling a month after a magnitude 7.5 quake which killed at least 100 people as landslides buried villages