Ms Sikder told the BBC the threats were made in a letter and a telephone call from a little-known group calling itself the Taleban Bahini (Taleban Force).

The group is believed to object in particular to a sculpture by Ms Sikder commemorating the role of women in Bangladesh's independence war against Pakistan.

Ms Sikder, who teaches at Dhaka's Fine Arts Institute, said she was threatened over the telephone and in a letter signed by the "Commander, Taleban Bahini." She was warned that she would be kidnapped and killed if she did not stop sculpting.

Earlier this year, an exhibition of Ms Sikder's work entitled "Struggle for Freedom" opened at Dhaka University. The exhibits showcased major events in Bangladesh's history.

Ms Sikder plans to continue working but has said she will take steps to protect herself.

According to AFP, Inspector General of Police Abdul Siddique said he had ordered an investigation into the threats.

"I have told relevant officials to deal with the matter and it is up to them how they will handle it," he said.

Militant attacks

A prominent Bangladeshi poet Shamsur Rahman was attacked by militants in January and the feminist writer, Taslima Nasreen, now in exile, says she has received many death threats.

Hundreds of militants held regular demonstrations against Ms Nasreen during her four-month stay in Bangladesh to be with her dying mother. She left the country in January.