The United States is strongly condemning the bomb attack on an opposition rally in Bangladesh Thursday that killed five people including a former cabinet member. The State Department urged quick action by the Dhaka government to resolve the case and prevent a climate of impunity from taking hold in the South Asian country.

The State Department is calling for speedy action by Bangladesh authorities in bringing to justice those behind Thursday's attack, and it is urging all political factions there in the meantime to exercise maximum restraint.

The comments follow a grenade attack on an opposition Awami League rally in northeastern Bangladesh Thursday that killed five people including former Finance Minister Shah A.M.S. Kibria.

The veteran politician and diplomat, who had just finished a speech when the attack occurred, died of multiple wounds several hours after the incident.

It touched off violent protests by Awami League supporters near the site of the attack, and in Dhaka.

The State Department strongly condemned the incident, which it said was the latest in a disturbing series of attacks on leaders of the Bangladeshi opposition and civil society, and the second fatal attack on an Awami League rally in six months.

Department spokesman Steven Pike called the incident an assault on the principles of free speech, democracy and peaceful political opposition and said the Dhaka government needs to resolve the case quickly:

"The failure to bring to justice the perpetrators of acts of political violence fosters an intimidating climate of insecurity and impunity that encourages further attacks," he said. "The Bangladeshi government needs to act quickly to identify, arrest and prosecute those responsible for political terrorism."

The Awami League leader Sheikh Hasina, who survived a grenade attack at a Dhaka rally in August that killed more than 20 people, has charged that the latest incident is part of a conspiracy by the government to eliminate its opponents.

A government spokesman in Dhaka denied what he termed the unfortunate allegation by Sheikh Hasina, and said authorities will thoroughly investigate the attack.

Spokesman Pike said the United States reiterates its steadfast support for Bangladesh's democracy.

He said all Bangladeshis should exercise maximum restraint, even under what he termed these difficult circumstances, to pursue their political objectives and search for justice peacefully.