Indonesia Earthquake: The quake was also felt on Indonesia's holiday island of Bali. (Representational)

A deep earthquake of magnitude 7.5 struck off the coasts of East Timor and Indonesia on Monday, the U.S. Geological Survey (USGS) said, and Pacific monitoring authorities ruled out the chance of tsunami.

Strong shaking caused alarm in the East Timor capital of Dili, prompting people to run out of their houses, a Reuters witness said, but there were no immediate reports of deaths or damage.

The quake was also felt on Indonesia's holiday island of Bali, several people said on social media. But there were no immediate reports of damage or injury in Indonesia, said Rita Rosita, an official of the national disaster mitigation agency.

The shaking was also felt in Australia's northern city of Darwin, about 700 km from the epicentre, the Australian Broadcasting Corporation said, but no damage was reported.

The quake, initially recorded at a magnitude of 7.2, hit out at sea at a depth of 220 km, the USGS said.

There is no tsunami threat because of the quake's depth, the Hawaii-based Pacific Tsunami Warning Center said in a statement.