Dhaka: Two-time former Bangladeshi prime minister Khaleda Zia has been sentenced to five years in jail for misappropriating funds meant for orphans, court officials say.

The special court in Dhaka issued the sentence on Thursday against the 72-year- old politician, who heads the opposition Bangladesh Nationalist Party, after convicting her for transferring 21 million taka ($320,000) to personal accounts from a charity.

The swindled funds were a grant to the Zia Orphanage Trust, the charity named after Zia's slain husband Ziaur Rahman during her 1991-96 tenure as prime minister.

The court also sentenced her son Tarique Rahman, who lives in exile in London, and four others to 10 years in jail.

Zia is the second head of the government convicted of graft charges, after former military dictator Hussain Muhammad Ershad.

Immediately after the court's decision, Law Minister Anisul Huq said the verdict showed that "no one is beyond law".

The BNP rejected the ruling as politically motivated.

"It is a personal and political vengeance of the prime minister," BNP leader Ruhul Kabir Rizvi Ahmed said, calling on party activists to scale up peaceful protest across Bangladesh.

Before the verdict police used tear gas on protesting supporters of Zia in Dhaka.

Security was tight across the country in anticipation of the judgement by the special court in Dhaka with police checkpoints set up across the capital.

Zia served as prime minister from 1991 to 1996 and then from 2001 to 2006.

AAP