DHAKA (Reuters) - A court in Bangladesh issued warrants on Sunday for the arrest of four suspected members of a banned group, Jamaat-ul-Mujahideen Bangladesh (JMB), in connection with the killing of a Japanese citizen last year, a prosecutor said.

Kunio Hoshi, 65, was gunned down in October by masked men on a motorcycle while on his way to visit a grass farm project in the northern district of Rangpur, less than a week after an Italian aid worker had been killed in a similar way in Dhaka’s diplomatic quarter.

The court issued the arrest warrants after deciding to press ahead with proceedings against four other suspected members of the outlawed group, public prosecutor Nayan Noor Rahman told reporters.

Police believe that the group, which has pledged allegiance to Islamic State, carried out a July 1 attack on a cafe in which 22 people were killed, mostly foreigners, before security forces ended a 12-hour siege, killing five gunmen.

Islamic State and al Qaeda have claimed a series of killings of liberals and members of religious minorities in Bangladesh in the past year.

Islamic State also claimed responsibility for the cafe attack but the government has dismissed suggestions the group has a presence in Bangladesh.

While authorities blame the violence on domestic militants, security experts say the scale and sophistication of the cafe attack suggested links to a trans-national network.