Two buses have been firebombed and explosives detonated in Feni as the BNP motorcade carrying Chairperson Khaleda Zia passed through the area on its way back to Dhaka from the Rohingya refugee camps.
The incident occurred around 4:30pm on Tuesday as the motorcade drove past Feni's Mahipal area.
Violence erupted in the area, causing disruptions.
On Saturday, when the BNP motorcade was on its way to Chittagong, several cars of the convoy came under attack by a group of unidentified men as soon as it passed Feni's Mohammad Ali Bazar area, around seven kilometres away from the district town.
The BNP motorcade had been scheduled to halt its journey at the Feni Circuit House on Tueday, but the plan was changed after a morning delay.A few hundred activists of the local Chhatra Dal and its allies came to escort the BNP chief on her way through Feni.
After several cars in the front of the convoy, including the one carrying Khaleda, drove past the Mahipal Filling Station around 4:30pm, two explosions were heard.
Soon after, two buses parked on the opposite lane of the highway were seen afire.
Alauddin Pathan, a leader of the BNP's Feni district unit, was in one of the cars in the convoy.
"As 15 to 20 cars, including the BNP chief's one, drove past, the buses were on fire and we heard explosions," he told bdnews24.com, adding he was merely 15 to 20 yards from the burning buses.
Following the explosions and arsons, local BNP activists, who had gathered to greet the party chief, demonstrated on the highway.Feni BNP president Abu Taher blamed Awami League stalwarts for the violence.
"It was a pre-planned thing, executed by the ruling party activists," he told local reporters.
Feni Awami League President Abdur Rahman denied the allegation saying the violence was an outcome of 'BNP's internal feud.'
On Saturday, the BNP motorcade had also been attacked near the border of the Feni district as it made its way towards Chittagong.
Nearly 30 vehicles belonging to the media covering the convoy were vandalised. Several journalists were assaulted, even after they identified themselves. The BNP and the Awami League have blamed each other for the attack.
BNP chief Khaleda's four-day tour to visit the refugee camps in Cox's Bazar ended, when she reached her residence in Dhaka's Gulshan just before 9pm on Tuesday.
The former prime minister started on Saturday and spent the night in Chittagong before heading for Cox's Bazar the next morning.
She returned to the port city the same day after visiting several refugee camps and headed for Dhaka on Tuesday morning.