DUBAI?- An earthquake measuring magnitude 6.3 struck on Tuesday 89 km (55 miles) southeast of the city of Bushehr in Iran, where the country's only nuclear power station is located, the US Geological Survey (USGS) reported.

The Iranian Seismological Centre at the University of Tehran reported a quake of 6.1 magnitude whose epicentre was Kaki, around 60 miles south of Bushehr, a port city on the Gulf.

Reuters witnesses felt the quake across the Gulf in Dubai, and Twitter users in Bahrain reported that offices in Manama had been evacuated after it struck.

The USGS said the quake struck at 1152 GMT at a depth of 10 km.

There was no immediate word on damages.