Relatives of foreign hostages murdered in a Bangladeshi restaurant were in Dhaka on Monday to take their loved ones' bodies home as authorities made the first arrests over the killings. Many were in tears as Prime Minister Sheikh Hasina laid wreaths on the coffins of those killed in the siege at an upmarket cafe in the capital, by far the deadliest in a spate of recent attacks that have caused international alarm. They included nine Italians, seven Japanese, a US citizen and a 19-year-old Indian student, whose body was flown home on Monday morning. Witnesses say the perpetrators of the attack, which Daesh has claimed, spared the lives of Muslims while herding foreigners to their deaths, killing many with machete-style weapons. Among the mourners at the ceremony in a Dhaka stadium was Muksedur Rahman who described slain Italian textile trader Nadia Benedetti as a "great human being" who had worked to help Bangladeshi survivors of acid attacks. "Nadia Benedetti had been working in Bangladesh for more than 20 years," Rahman, a colleague of the Italian, said. "I can't believe she had to die like this. We have to stand against such terrorism right now." The government said the bodies of the Italian and Japanese victims would be handed over to diplomats before being flown home. Italy's ambassador Mario Palma said Friday night's attack on the Holey Artisan Bakery cafe was "unprecedented" and promised his country's full support in tackling a rise in Islamist militancy in Bangladesh. Commandos killed six suspected militants in the final stages of the siege, but one was taken alive. On Monday police formally arrested him and one other suspect. "Two suspects are in our custody. One of them is injured and is hospitalized," said police inspector general Shahidul Hoque. Survivors told police all the victims were killed within the first 20 minutes of the attack, he added. Police also raided the home of a survivor after images showed him walking around the restaurant compound during the siege, but found no evidence against him, local media reported. US Secretary of State John Kerry offered Washington's support in a telephone call to Hasina, whose government has been unable to stop a wave of Islamist attacks on foreigners and religious minorities in officially secular but mostly Muslim Bangladesh. "(Kerry) encouraged the government of Bangladesh to conduct its investigation in accordance with the highest international standards and offered immediate assistance from US law enforcement, including the FBI," said his spokesman John Kirby. The government has repeatedly denied international terror networks have a presence in Bangladesh, though the Daesh-linked news agency Amaq published extensive details of Friday's attack, including photos from inside the cafe. Analysts say the government is wary of acknowledging such groups are operating in Bangladesh for fear it could frighten off foreign investors. But it has been criticized for failing to tackle a rise in militant attacks. Home minister Asaduzzaman Khan said on Sunday the attackers were members of the Jamaeytul Mujahdeen Bangladesh (JMB), a local militant group banned by the government. He said there were cases against all of them, but denied any intelligence failures ahead of the assault on the cafe, which came after a major crackdown that saw around 11,000 people arrested, some of them known extremists. Critics allege the arrests were arbitrary or designed to silence political opponents. Earlier the transport minister Obaidul Quader said six of the Japanese killed were consultants for Bangladesh capital's first metro rail, and expressed hope Tokyo's foreign aid agency would continue its support for the three billion dollar project. "Japan knows that this attack was part of the global terrorist activities. I hope they'll understand the reality," he said. "There is no question of stopping this project."