An earthquake measuring 5.3 on the Richter scale on Monday shook the tsunami-hit Indonesian province of Aceh, where more than 20 aftershocks have been reported since a powerful earthquake triggered a tsunami on Dec. 26.

The tremor occurred at 10:08 local time (03:08 GMT) Monday and lasted for about 20 seconds, the provincial geophysics agency reported, as quoted by the Antara news agency.

The epicenter was located beneath the water off Sumatra island, about 30 km northwest of the Aceh provincinal capital of Banda Aceh.

The quake caused panic among residents but there was no report of casualty.

(Xinhua News Agency February 1, 2005)