Jakarta  - An explosion heavily damaged a drugstore in the central Java city of Yogyakarta on Thursday, injuring three people, police and media reports said.

Yogyakarta police chief Brigadier-General Sunaryono said the explosion was caused by a low-level explosive and occurred at 8:10 am (0110 GMT). It badly damaged the drugstore building.

However, Sunaryono said the blast was not believed to have been an act of terrorism.

"The cause is still unknown, but it is not related to terrorism," the state-run Antara news agency quoted Sunaryono as saying.

Two of the three lightly injured people were reportedly store employees, while the third was a man passing by on a motorcycle when the explosion took place. (dpa)