Dhaka  - Bangladesh's opposition leader Khaleda Zia Thursday promised to play a constructive role in parliament, which is scheduled to convene later this month.

"We want to help the government. But the government must reciprocate," Zia, who was formally endorsed leader of the opposition in parliament by deputies from her Bangladesh Nationalist Party (BNP) at a meeting immediately after they were sworn in as lawmakers Thursday.

The BNP was defeated in general elections late last month, securing only 30 out of 300 parliamentary seats.

At a press conference after the swearing in ceremony, Zia accused her political arch-rival Sheikh Hasina Wazed if the Awami League party, which won a landslide victory and formed the government, trying to crush the opposition.

Zia alleged that ruling party officials had launched a massive cleansing campaign against opposition supporters, killing as many 17 people in post-election violence across the country.

Zia has also alleged unacceptable fraud in the December poll and called on Hasina to enable opposition parties to play their due role in parliament.

Bangladesh's ninth parliament is to hold its first session on January 25. (dpa)