A 6.1-magnitude earthquake shook the Indonesian island of Sumbawa on Wednesday but caused no immediate casualties or damage, police and meteorologists said.
The quake struck at 9.45pm local time and was centered about 300km southwest of Taliwang town, said a spokeswoman from the main meteorological agency in Jakarta.
She said the quake, which had an epicenter 33km under the sea, was strong enough and shallow enough to cause a tsunami within 45 minutes.
But police on the island speaking around 90 minutes after the quake, said they had received no reports of a tsunami, nor of any casualties or damage.
"Until now, no incidents after the quake have been reported to us," a local policeman called Firman said by telephone.
The 6.1 reading was based on the open-ended Moment Magnitude scale, now used by US seismologists, which measures the area of the fault that ruptured and the total energy released.
Early yesterday, a moderate 5.1-magnitude quake was recorded 194km south-southeast of Banda Aceh, the capital of Aceh province on the Indonesian island of Sumatra. Aceh Province was devastated by the December 2004 tsunami.
A 7.7-magnitude earthquake last month triggered another tsunami that lashed the south coast of Indonesia's Java island, killing more than 600 people.