Four strong earthquakes hit off southern coast of Indonesia

9news.com.au

Four earthquakes have struck waters south of Indonesia over five hours, with the strongest recorded as a 6.4 magnitude tremor.

The first of the four quakes struck at 7.59am (local time) in the ocean off the south-west coast of the Nusa Tenggara Timur island and north of Port Hedland in Western Australia.

The shake was measured as a magnitude 6.0 and extended 37 kilometres below the earth’s surface, according to the Australian Government’s Earthquakes GA website.

The Indian Ocean off the south coast of Indonesia has been struck by four earthquakes over five hours. (Supplied)

Nine minutes later, a magnitude 5.2 aftershock was also recorded in the same location at a depth of 45km. 

Less than an hour after that, another 5.2 struck before the magnitude 6.4 earthquake hit at 1.10pm just seven kilometres below the surface.

The last of the four tremors was so strong, seismologists believe it may have been felt up to 697km and as far away as Denpasar and Surabaya in central Indonesia, and as far east as Timor-Leste.

It may have also caused some structural damage up to 56km away from the quake's epicentre, according to seismologists.