An earthquake measuring 7.3 has struck near the Indonesian island of Sulawesi the US Geological Survey said.
It centred in the Molucca Sea at 1927 (1127 GMT), some 160km (100 miles) south-east of the city of Manado.
An official from the meteorology department in Jakarta said there were five aftershocks in the first hour.
Indonesian officials put the strength of the quake at 6.5 but said there was no longer risk of a tsunami following initial warnings.
A spokesman for the Hawaii-based Pacific Tsunami Warning Center had said there were dangers of a "localised" tsunami, stretching from 100-200km (60-125 miles) from the epicentre.
Indonesia was the worst-hit country in the Indian Ocean tsunami of December 2004, which killed more than 160,000 people in Aceh province.
"After one hour we called the port authority in Manado and there was no rise in sea level. Therefore we cancel the possibility of tsunami taking place," the meteorology department official was quoted by AFP news agency as saying.
The Associated Press news agency reported a witness on Sulawesi as saying that at least three residents were injured by the quake.
But Indonesian authorities said there were no reports of damage or casualties, AFP said.
The earthquake was centred some 51km under the seabed.