The Samoa Meteorological Service has issued a tsunami advisory after the country was rocked by a 6.9 magnitude earthquake at 5.01 am Thursday.

The earthquake, which measured 6.90 on the richter scale, had a depth of 10.00 km and was located in the Tonga region. 

"Tsunami advisory is in effect," reads a post that the MET put on its Facebook page at 5.13 am. 

The epicentre of the earthquake was 424.49 km southwest of Apia, according to the MET.

Residents in Apia reported that the tremor went on for about 3 minutes with some families running out of their houses after 5 am in the morning.

The Ministry of Natural Resources and Environment (MNRE) also issued a tsunami advisory at 5.20 am.

"An Earthquake with a magnitude of 6.9 has occurred within the Tonga Region, on Thursday 11th May at 05.01 am (Samoan Local Time). The depth is 10 kilometres and the distance in kilometres 422 km South West of Apia. The next bulletin will be issued in the next 30 minutes."

A Saleimoa resident, who spoke on condition of anonymity, told the Samoa Observer at 6.01 am Thursday that about 10 families have evacuated from the coast to Aleisa in the hinterlands of Upolu Island.

He said there were no sirens from the authorities, such as Samoa Fire and Emergency Services (S.F.E.S.A.) to alert the residents of the tsunami advisory issued by the authorities. 

"It surprised me that some families are still asleep, even our pulenu'u (village mayor) didn’t ring the bell, we are not hearing any sirens from emergency services like S.F.E.S.A.," the villager said. 

"Almost all families are complaining that they are unaware. I am so surprised that the earthquake was so strong and some families didn’t feel it and wake up but we have now evacuated to Aleisa." 

The MET issued another update on its Facebook page at 6.21 am to advise the public that their tsunami advisory remains in effect and they should wait for further updates from their office. 

• This is a developing story....