Supporters of an opposition group in Bangladesh, the Awami League Party, on Friday protested the killing of five party members, including a senior party official. They were slain in the latest in a series of attacks targeting the opposition. A powerful explosion ripped through an Awami League rally on Thursday in the northeast town of Laskarpur shortly after former Finance Minister Shah A.M.S. Kibria had given a speech. Mr. Kibria, who was also a former executive secretary of the Bangkok-based United Nations Economic and Social Commission for Asia and the Pacific, died of his injuries in a Dhaka hospital. The grenade attack killed four other people and injured scores. Angry Awami League supporters took to the streets Friday in Mr. Kibria's home town, Hobiganj, demanding the arrest of his killers. The party called for a countrywide strike on Saturday. A senior Awami League leader, Saber Hossain Chowdhury, asserts that the attack is part of a government-backed campaign to eliminate democratic and secular forces in the country. "This is a trend we have been witnessing with great concern," he said. "We feel the theater of terrorism has moved to Bangladesh and there is growing radicalism and extremism which is holding the country hostage." Thursday's attack comes six months after Awami League leader and former Prime Minister Sheikh Hasina narrowly escaped injury during a grenade attack on a rally she was addressing in Dhaka. More than 20 people were killed and hundreds injured in that incident. A string of bomb blasts in Bangladesh in the past 18 months have killed scores of people. Several of the attacks have targeted the political opposition. So far authorities have made no headway in identifying or detaining those behind the attacks. Mr. Chowdhury says the government must take responsibility for not bringing those behind the attacks to justice. "What the government, through its inaction or choosing not to act, is doing is encouraging these terrorists to continue these attacks," he said. "And we are concerned that there will be further attacks in the future." The government strongly denies the opposition charges and says it is investigating the incidents. It says it is working hard to improve a poor law-and-order situation inherited from the previous Awami League administration. The latest incident comes a week before Bangladesh hosts a summit of South Asian leaders.