The quake, which registered a magnitude of 5.8, struck at 7:06 a.m. local time about 45 miles south-southeast of Denpasar, Bali.
Most of the injured were struck by debris or jumped from buildings during the terrifying quake.
"When the quake happened, I was in a market and some people started shouting and running out of the market building, leaving their belongings behind," Putu Suartana, a resident in Singaraja in Bali, was quoted as saying by the Reuters news agency.
Earlier this month, a 7.0 magnitude quake killed at least 80 people and wrecked hundreds of buildings on the neighboring Indonesian island of Java.