Chowdhury, who was the home minister in the 2001-2006 BNP-led government, was on his way to the Kalaparha municipality to campaign on behalf of the party’s mayoral candidate.
Local BNP leaders claimed at least 10 people, including the former minister’s wife Suriya Chowdhury, were injured.
His motorcade came under attack around 10am in Kalaparha town’s Rahmatpur locality, police said.
“It’s unclear who the attackers were but the windows of four vehicles have been smashed,” said Kalaparha police OC Azizur Rahman.
“At least five vehicles were damaged,” said Chowhdury, claiming he, too, had been injured.
Meanwhile, local journalists have said the miscreants snatched their mobile phones and cameras.
But the gadgets were later returned by activists of the ruling party’s affiliated student body, said Boishakhi TV’s Patuakhali Correspondent Abdus Salam Arif.
The local unit of the Awami League has denied any hand in the incident.
“It happened because of a feud between BNP leaders Altaf Hossain Chowdhury and ABM Mosharraf Hossain,” said Patuakhali town unit AL Vice President Masum Bepari.