Police say eight people have been injured in an attack on a passenger van in Nepal's capital during a transport blockade called by opposition parties attempting to disrupt next week's elections.

Police said a gasoline bomb was hurled at the van during the evening rush hour Wednesday, burning those inside. The attackers fled and police are searching for them. No one has claimed responsibility for the attack.

Wednesday is the second day of a nine-day transport blockade called by an alliance of 33 opposition parties demanding a stop to next Tuesday's polls and a change in government.

Opposition activists have set fire to buses, trucks and cars since Monday to enforce the blockade.