The quake in Indonesia came as a major 7.0-magnitude earthquake struck PNG's New Britain island, briefly triggering a tsunami alert before authorities gave the all clear, various media outlets reported.
The United States Geological Survey said the PNG quake hit about 125km east of Kimbe around a depth pf 40km.
There were a string of smaller tremors measuring up to 6.2 immediately before and after the main earthquake.
The magnitude 7.0 quake was followed by aftershocks of magnitude 5.7 and 5.9.
Just more than an hour later, a magnitude 6.3 quake hit further northeast on the island.
The Pacific Tsunami Warning Center initially warned hazardous tsunami waves were possible in coastal areas 300km from the epicentre.
At least three people were killed when the shallow 6.0-magnitude earthquake struck off the coast of Indonesia's popular tourist hotspots.
The victims in East Java's Sumenep district perished after being crushed by collapsed buildings, national disaster agency spokesman Sutopo Purwo Nugroho said.
"The earthquake happened early on Thursday when they were sleeping and the quake suddenly rocked so they didn't have time to evacuate," he said, adding that damage caused by the tremor was not widespread.
The strong quake was felt in Denpasar on the holiday island of Bali, where panicked people fled from buildings.
The quake near Bali caused brief panic among residents, although there was no tsunami alert issued.
"I felt it for about 10 seconds. People were sleeping but got woken up by it," Tonny Akbar Mahendro told AFP.