About five gunmen killed Madhab Sarkar, 35, son of Brindaban Sarkar, and his nephew Bhushan Sarkar, 30, son of Ballabh Sarkar, at their Bishal Silver Store under Kotwali Police Station at around 3:45pm.

Thousands of goldsmiths, labourers and locals in black badges marched in a procession at Tantibazar with the corpses yesterday, demanding punishment of the killers.

"We keep closed ours around 20,000 gold stores from the morning," said Babu Ranjan Sarkar, president of Tantibazar Banik Samity.

The gold traders also hung black banners in protest against the killings.

Three bodies of gold traders -- Bangladesh Poddar Samity, Swarnashilpi Sramik Sangha and Bangladesh Pathar Samity -- declared a three-day protest programme.

Leaders of the combine have asked the law enforcement agencies not to harass innocent traders 'in the name of investigation'.

They also demanded beefed up security measures fearing extortion and further attacks and proper investigation into the killings.

Additional police have been deployed in the area.

The lone arrestee in the case, Swapan Dhar, who was arrested on Sunday, was remanded for three days yesterday. He is an notorious gunman in the locality, locals say.

Gold traders and the victims' families suspect extortion and previous enmity, among other reasons, were behind the killings.

"Madhab, a former goldsmith who had become the owner of a shop, had a feud over the ownership of his store with a local trader," said Babu Ranjan Biswas, president of Tantibazar Banik Samity.

Santosh Kumar Roy, president of Pathar Samity, told reporters extortionists might have killed the two.

Madhab's brother Ballabh Chandra Sarkar suspects a few absconding convicts, who abducted and raped two relatives of the family two years ago, committed the murders.

"They had been threatening us with death since the incident," said Ballabh, a primary schoolteacher.

Local ward commissioner Sarika Sarkar suspects extortionists killed the gold traders.

Her husband, Binoy Krishna Sarkar alias Bina, a former ward commissioner, and his gunman were gunned down three years ago allegedly by extortionists.

Dakaat Shahid, the absconding charge-sheeted accused in the Binoy murder case and convict of the Advocate Habibur Rahman Mondol murder case, killed the two, said a trader asking not to be identified.

"Shahid's close aides might have killed the two at his directive," the trader added.