The fourth nationwide strike in seven days has shut down Bangladesh. It was called by opposition parties that accuse the government of helping plot last week's deadly attack on an opposition rally.

The strike successfully shut down most of Bangladesh for the day. The normally congested streets of Dhaka, the capital, were largely empty. Schools, stores and offices were closed, and most people stayed indoors.

The 24-hour strike is a protest against an attack on an opposition political rally nine-days ago. Unknown assailants lobbed at least seven grenades into the crowd, killing 19 people and injuring more than 300 others.

The Awami League, the leading opposition party, says the attack was an attempt to assassinate the party's leader, Sheikh Hasina Wajed. The party accuses the government of involvement in the attack and is demanding that the prime minister resign.

"[The] demand of the people of this country is that this government should go and that demand has become the demand of this nation," says Awami League General Secretary Abdul Jalil. "Everybody is demanding this government should go, because it has lost credibility."

Mr. Jalil accuses the government of impeding investigations into the attack and covering up any ties it might have to the attackers.

The prime minister, Begum Khaleda Zia, has rejected any association with the attack and her government has condemned it. The government has welcomed a two-man team from Interpol, the international police organization, which will help lead the investigation, and a $160,000 reward has been offered for information leading to the arrest of the perpetrators.

Government supporters say the opposition is using the attacks as an excuse to undermine the prime minister. Business leaders have been urging an end to the strikes, which they say are costing the impoverished nation more than 60-million dollars a day.

But the Awami League's Abdul Jalil defends the repeated strikes, known locally as "hartal," and says the opposition will not rule out further actions in the days ahead. "We are facing more economic loss by the existence of this government because this government has totally failed to give security in all sectors of life in society," he says. "That is causing more damage economically than by calling hartal."

A series of mysterious bombings, some targeting opposition figures, has killed more than 100 people and injured hundreds more over the past several years, but no arrests have been made.