Bangladesh Rapid Action Battalion (RAB) personnel stand alert at the entrance to a camp Friday, after an attempted suicide bomb attack.
The Islamic State Group claimed responsibility Saturday for a suicide bomb attack on a Bangladesh security forces camp, while police in Dhaka shot dead a suspected militant in a separate incident.
The Bangladeshi government has repeatedly denied the presence of IS in the country, blaming attacks on local extremists.
"A caliphate soldier in Bangladesh carried out a martyrdom operation with an explosive belt in a camp for special forces in Dhaka," IS announced in its daily al-Bayan radio bulletin Saturday.
Two policemen were wounded in the apparently botched attack on Friday when a man blew himself up at an elite forces camp near Dhaka's international airport.
The camp attacked was occupied by the Rapid Action Battalion (RAB), an elite force tasked with combatting militancy.
Asked about IS' claim of responsibility, RAB spokesman Mufti Mahmud Khan told AFP: "IS has no presence in Bangladesh at all".
The Islamic State group claimed responsibility for a major attack on a Dhaka cafe last year in which 22 people, including 18 foreign hostages, were killed.
The Bangladeshi government however has said a new faction of homegrown extremist group Jamayetul Mujahideen Bangladesh (JMB) was behind that and other attacks.
Critics accuse Prime Minister Sheikh Hasina's secular government of using the spate of attacks in the country to demonise her domestic opponents.
On Saturday a man on a motorbike tried to cross a RAB security roadblock in Dhaka carrying a bag with improvised explosive devices.
Bangladesh police shot the suspected militant dead, Khan said.
"As he was carrying explosives we primarily suspect him of being a militant," Khan told AFP, adding further investigation was needed to ascertain his identity.
A bomb disposal unit recovered the biker's bag containing multiple small improvised bombs, which were later defused, Khan said.
Friday's bomb attack was one of the first in recent years against the elite RAB force, which has led a nationwide crackdown on Islamist extremists, arresting scores of suspects.
Police have this month also been carrying out a series of raids in the southern Chittagong region and say they killed four suspected militants when they stormed an extremist hideout on Thursday.
Former US Secretary of State John Kerry said last year there was evidence to link extremists behind attacks in Bangladesh to IS.
"There is the ideological footprint of IS in Bangladesh, there is no denial about it," said Shahab Enam Khan, a terrorism expert at Jahangirnagar University.
"However, we have not received enough evidence of their physical existence in concrete organisational form in the country yet."