New York, Dec 17 (IANS): Bangladesh should publicly order security forces to avoid using lethal or excessive force when dealing with protesters, Human Rights Watch said Tuesday.

The leaders of all political parties, including Jamaat-i-Islami and the Bangladesh Nationalist Party (BNP), should keep supporters from engaging in violence, it said.

The government should set up an independent commission to carry out prompt, effective and impartial investigation into the violence and hold all those responsible to account.

Security forces appear to have stepped up operations against the opposition in recent days.

Jamaat supporters have attacked police posts, government buildings, ruling party activists and Hindu communities.

Media reports say that security forces have killed at least 20 opposition members during clashes and have arrested many more.

More than 100 people have been killed and hundreds injured in the past two months since the political crisis in Bangladesh began over upcoming elections and the conduct of war crimes trials.

The crisis worsened following the Dec 12 execution of a leader of the Jamaat party, Abdul Qader Mollah, who was found guilty of war crimes during Bangladesh's independence war in 1971.

Jamaat activists allege that many of their colleagues have been wrongfully arrested and mistreated by the police.