One of the vehicles belonged to a television channel.
The BNP and its allies have been calling such shutdowns since the beginning of February alongside its ongoing and indefinite nationwide transport blockade that started from Jan 5.
The coalition wants a snap national poll under a nonpartisan caretaker dispensation.
Police and witnesses said the vehicles were set ablaze around the same time on Saturday evening.
There were, however, no casualties in these incidents.
A bus and a covered van were set on fire at Jatrabarhi around 6:30pm, said Jatrabarhi Police Station Sub-Inspector Md Shahjahan.
A microbus of Desh TV and two other cars were torched in front of the TV station’s office at Mouchak around the same time.
The building also houses the offices of Daily Bhorer Kagoj.
The daily’s senior journalist Kamruzzaman told bdnews24.com that the troublemakers exploded at least 10 crude bombs at that time creating much panic for a while.
Around 7pm, suspected pro-blockade elements set fire to another bus at Banani, police said.