The Islamic State (Isis) has claimed responsibility for shooting dead an Italian aid worker in Bangladesh marking the expansion of the extremist group. The incident took place in the diplomatic zone in Bangladeshi capital, Dhaka.

Bangladeshi police have confirmed Cesare Tavella, aged about 50, has died at the hospital following gunshot wounds. But the authorities did not specify whether the IS was behind the attack.

"Probably they [assailants] were following him. Another person stood at one end of the Road 83 parking his motorcycle in front of the German Development Cooperation Building," Mohammad Mosharraf Hossain, who took the Italian national to a nearby hospital, told bdnews24.com. "I could not identify them as the streetlamps were off. One of the two persons behind him shot him after sometime. I heard three gunshots."

An initial probe by local officials suggests the attack, which took place on Monday, 28 September evening, was planned. Subsequent to the gun-attack, the Iraqi-based Sunni Islamist group claimed responsibility for the assault.

"Based on the evidence and previous experience, we could say that the murder was pre-planned," senior police official Mukhlesur Rahman told reporters after visiting the crime scene. Tavella was thought to be working with a Netherlands-based NGO.

According to the SITE intelligence group, the IS released a statement in Arabic claiming a "security detachment" was following the Italian citizen and later killed him with "silenced weapons". Their claim is yet to be independently verified. If confirmed, the incident would be the first such attack by the group in the South Asian nation.