The Brazilian government has appointed an army general to oversee security in the state of Rio de Janeiro, in response to growing gang violence.

President Michel Temer compared the violence to “a cancer” and said organised criminals had all but seized control of the state.

Rio’s governor issued an appeal for help after the annual carnival celebrations were marred by violence.

The army will oversee police and other security services.

Overseeing the operation will be Gen Walter Souza Braga Netto, head of the Eastern Military Command. He was widely praised for his part in co-ordinating security for the 2016 Rio Olympic Games.