Twenty people have been killed in an attack on a cafe in Bangladesh claimed by so-called Islamic State.Six attackers were also killed and one was arrested, officials said. Bangladeshi PM Sheikh Hasina has declared two days of national mourning.Nine Italians, seven Japanese, one US citizen and an Indian also died.Bangladesh Army Brig Gen said the victims had been "brutally" attacked with sharp weapons. Bangladesh's Daily Star newspaper said the gunmen tortured anyone who was unable to recite the Koran. "It was an extremely heinous act," Ms Hasina said in a televised statement. "What kind of Muslims are these people? They don't have any religion". The offenders were 7, they are almost 20 s, and not poor, and educated. They have been trained several months in the foreign Islamic country before attack. They were young people who were influenced devilish religion. There are many devilish people in the world. I worry about them always, although there is enormous difficulties in front of us,