Dhaka  - Heavy small arms and mortar fire erupted inside the central Dhaka headquarters of the Bangladesh Rifles on Wednesday morning, sparking fears of a military uprising.

Regular army troops attempting to enter the headquarters were fired on and turned away by the solders inside the compound.

Witnesses said several helicopters were approaching the Bangladesh Rifles border security force headquarters but could not confirm they had been fired upon.

Regular army units and police were seen evacuating civilians from the vicinity of the central Dhaka military compound. No casualty figures were immediately available.

"We cannot tell if it's a coup, but there have been rumours about discontent about the promotion of some officers," one witness outside the army barracks said in a telephone interview.

He said the shooting broke out at about 8:30 am (0230gmt) and the army camp has been sealed off since then.

Bangladesh returned to civilian rule in December after two years under a military-backed government. (dpa)