There have been angry protests in Bangladesh following the killing on Thursday of a prominent member of the opposition Awami League.
Opposition protesters in Dhaka
Former Finance Minister Shah AMS Kibria and four others were killed in a grenade attack after he had addressed a rally in north-eastern Bangladesh.
In August, Awami League leader, Sheikh Hasina, survived a grenade attack on a rally in which 22 people were killed.
The Awami League has called for four days of nationwide protests.
Sheikh Hasina told the BBC the attack on Mr Kibria was part of a conspiracy by the government to eliminate its opponents.
Government spokesman Haris Chowdhury described the allegations as unfortunate and denied any government involvement in the attack.
He said the administration had already called for a thorough investigation into the incident.
So far there have been no arrests.
In the district of Habiganj, where the attack took place, Awami League members attacked shops and vehicles.
Shah AMS Kibria - a veteran politician and diplomat
In the capital, Dhaka, demonstrators chanted anti-government slogans and several vehicles were set on fire at Dhaka University.
Mr Kibria, a 73-year former diplomat, was critically wounded when a grenade was hurled at the crowd after he finished his speech at a political rally at Laskarpur, about 250km from Dhaka.
He was rushed to Dhaka by ambulance but he was declared dead shortly after midnight.
A doctor said he died of bleeding from wounds to the head, stomach and legs.
One of the four others who died was a nephew of Mr Kibria.
Thousands of people attended funeral prayers for Mr Kibria at the national mosque in Dhaka on Friday.
His body was later taken to the Awami League party headquarters in central Dhaka for more prayers before burial.