Image copyright AFP/Getty Image caption The US and Britain have urged their citizens in Bangladesh to be cautious after the killing of an Italian aid worker

Bangladesh police are investigating the murder of an Italian aid worker who was shot on Monday night.

The Islamic State group says it carried on the attack, shooting dead Cesare Tavella, 50, in the capital Dhaka's diplomatic quarter.

Police Commissioner Asaduzzaman Mia said Tavella was jogging when two attackers fired at him from behind.

The US and UK urged citizens to be cautious, saying they had information Western interests could be targeted.

They have also restricted the movements of their diplomats.

The BBC's South Asia editor Joanna Jolly says it is the first time IS has claimed an attack in Bangladesh, where it has not yet announced a branch.

In its claim, IS warned that "citizens of the crusader coalition" would not be safe in Muslim nations.

Police in Dhaka have not commented on the IS claim.

Bangladesh has been struggling to respond to a recent rise in radical Islamist groups.

Extremists have carried out a series of high-profile attacks on secular bloggers, hacking to death four bloggers - one a US citizen - so far this year.

One group, Ansarullah Bangla Team, has reportedly threatened to kill secular bloggers and activists outside Bangladesh. The group was outlawed in May.

Last week, the Australian cricket team delayed its planned departure to Bangladesh after being warned there was a potential security risk.

The tour has not been rescheduled despite assurances from the Bangladeshi government that the players would have a full security detail.