Four people have been detained in Brazil in connection with the devastating nightclub fire that left more than 230 dead and over 110 injured.

　　Brazilian President Dilma Rousseff has announced a three-day national mourning period for the dead.

　　Adriano Yalo is a relative of victim killed in the fire.

　　"I think that public authorities are also responsible. It's a set of responsible parties that caused the fire. Not just one or two or three people, this includes the government, the firefighters, the owner of the nightclub. We're hurt."

　　Rio Grande do Sul state governor, Tarso Genro, paid a visit to the town of Santa Maria and spoke to some of the families. He stressed the need to find reasons for the causes of the tragedy.

　　"These detentions that have been made, don't get it wrong - no one has been charged, those detentions have been made to facilitate the investigations."

　　China has expressed its heartfelt concern for the victims of the nightclub fire. The country has also launched a nationwide campaign to reduce potential fire risks in public buildings.

　　UN Secretary-General Ban Ki- moon has also extended his condolences.