At least 18 people died and dozens were feared trapped in rubble after a strong 6.4-magnitude earthquake struck off Aceh province on Indonesia's Sumatra island on Wednesday.

"Eighteen have died so far, based on data from the hospital. Some of the fatalities are children," Said Mulyadi, deputy district chief of Pidie Jaya.

According to preliminary data, the number of destroyed buildings is 17, France24 reported.