Rescuers have evacuated 18 people and continued searching for 12 missing persons after a boat sank in eastern parts of Indonesia on Friday afternoon, rescuer said.

KM Karya terang boat sank at about 17:30 p.m. local time (1030 GMT), one hour after leaving Palue island in East Nusa Tenggara province toward Maumere district of the province, Head of Search and Rescue office in the province Hermanto da Gomes said.

"We have rescued safely 18 people out of about 30 people on board," he told Xinhua by phone from the province.

Gomes said that heavy rain with huge waves may cause the accident.

Having journey with boat or ship is a favorable transport mean in the archipelago country, but lack of safety standard and extreme weather condition have often caused sea accident.