Bangladesh authorities have put the police force on nationwide alert after the Islamic State group claimed responsibility for a second explosion targetting security forces in less than a month.
The Sunday night blast in Dhaka's Malibagh neighbourhood, just outside the headquarters of the police's Special Branch, left two people injured, including a female officer.
Dhaka Police Commissioner Asaduzzaman Mia told reporters Monday it was a powerful bomb, and that it had been planted in a police pick-up van.
Daesh claimed responsibility, with its propaganda wing Amaq saying the IS militants targeted the police vehicle with an "explosive device", destroying the vehicle and wounding three personnel on board.
Bangladesh police rejected the claim, saying the explosion was still being investigated.
"No connection of IS has been found in the incident," national police spokesman Sohel Rana said.
He said following the blast "all units of Bangladesh police have been asked to take necessary cautionary measures".
Last month, The IS group said they "detonated an explosive device" aimed at a group of police, the SITE Intelligence Group reported. It was the first IS-claimed attack in Bangladesh in more than two years.
According to the US-based SITE, which monitors jihadist activity, the brief IS statement said that blast wounded three police on a road to Dhaka's Gulistan market.
The IS group also said it detonated explosives in the northeastern city of Sylhet in March 2017.
Police said six people died in those blasts as commandos stormed an Islamist hideout. The government at the time rejected IS's claim and blamed a banned homegrown organisation.
Bangladesh launched a crackdown on Islamist extremism after attacks in July 2016, when IS-inspired militants stormed a Dhaka cafe killing 22 people, including 18 foreigners.
Since then, security forces have staged nationwide raids in which, they say, nearly 100 members of two extremist Islamist groups have been killed. Hundreds of suspects have been detained.
The South Asian nation has also boosted security since the April 21 Easter Sunday bombings in Sri Lanka, which were carried out by attackers affiliated to I group.