DHAKA - Western embassies in Bangladesh have restricted their diplomats’ movements amid concern more foreigners might be targeted after an Italian was shot dead in the first attack in the country claimed by Islamic State.

Some international schools and clubs in Dhaka were closed on Tuesday and police tightened security, stopping motorists and checking papers in areas frequented by expatriates.

Police have not confirmed the involvement of the hardline group, which has ambitions to spread into South Asia. Police in the Bangladeshi capital arrested two suspected recruiters for Islamic State this year.

Attacks on foreigners are rare in Bangladesh, despite a rising tide of violence over the past year that has seen four online critics of religious militancy hacked to death, among them a US citizen of Bangladesh origin.

If confirmed as the work of Islamic State, the shooting of Cesare Travella, a 50-year-old aid worker, would be the first attack in Bangladesh by the group based in Iraq and Syria.

In a communique translated by US security analysts SITE, Islamic State said a “security detachment” had tracked Tavella before shooting him with “silenced weapons” on Monday.

Tavella, who arrived in Bangladesh in May to run a food security project for the Dutch development group ICCO backed by Christian churches, had more than 20 years experience in rural development, mostly in Asia. He was shot in Dhaka’s diplomatic quarter by three gunmen on a motorcycle.

Tavella was shot with a revolver three times from behind at close range, said forensic expert Qazi Mohammad Abu Shama, who conducted the autopsy.

“One bullet hit his left hand and another pierced through his chest,” he told reporters on Tuesday.

“We are deeply saddened by the shocking news,” ICCO said in a statement.

In its statement, Islamic State hinted at more attacks in Bangladesh and said citizens of what it called “the crusader coalition” were not safe, even in the homes of Muslims.

As well as aid workers, Bangladesh is frequented by a steady flow of foreign buyers and executives involved in the country’s $24 billion garment export industry.

The government is fighting to restrain radical Islamist groups, who want to turn the Muslim-majority South Asian nation of 160 million into an Islamic state.

The US embassy said its diplomats were instructed not to go outside overnight after Monday’s shooting and warned of possible attacks on US facilities, citizens and interests.

“In light of the increased threat, US citizens should consider limiting their attendance at events where foreigners may gather, including events at international hotels,” it said in a statement late on Monday.

Australia, Britain and Canada also told embassy officials to avoid events where Westerners may gather and warned of possible attacks in “late September”.

The motive for Tavella’s shooting was unknown, said acting inspector general of police Mokhlesur Rahman.

“But, based on our experience, we can say it is a pre-planned murder,” he told reporters after visiting the crime scene in the Gulshan neighbourhood, home to several embassies.

Another police officer investigating the shooting said Tavella’s belongings had been left untouched, which appeared to rule out theft as a motive.

Last week, the Australian cricket team delayed its planned departure to Bangladesh after being warned of a potential security risk from militants. The side were due to fly from Sydney on Monday morning for the three-week tour.