Twenty people, most said to be foreigners, were killed during an attack by suspected Islamist militants on a cafe in Bangladesh, the army says, according to BBC News.

Gunmen stormed the Holey Artisan Bakery cafe in Dhaka late on Friday, July 1 before troops entered almost 12 hours later.

Six of the attackers were also killed and one was arrested, a government spokesman said. The attack was claimed by the so-called Islamic State (IS).

Italy's PM Matteo Renzi confirmed that Italians were among the dead.

He offered condolences to the victims' families and, referring to the attackers, said: "Our values are stronger than hatred and terror."

Italian news agency Ansa said up to 10 Italians may be unaccounted for. The Italian press said many of those dining at the cafe worked in the garment industry.

The army had initially said all hostages killed were foreigners, but Reuters, Associated Press and local media said some Bangladeshis also died.

The siege began as diners were gathering to break their fast during the Muslim holy month of Ramadan.

Bangladesh's Daily Star newspaper said the gunmen tortured anyone who was unable to recite the Koran. They provided meals overnight for only the Bangladeshi captives, it said.