The Brazilian city of Sao Paolo remains in a state of high tension after a weekend of attacks on police and related prison riots which have left at least 30 people dead.Stand-offs are continuing in some of 20 jails around Sao Paulo state where inmate uprisings erupted on Friday. They were part of a coordinated reacton to the transfer of 600 criminal gang members to a high security prison. Dozens of people are thought to have been taken hostage in the rebellions orchestrated by the gang, known as the First Command of Capital. The attacks on police in Sao Paolo city have been described by the state’s top security official as a “show of force” by the criminals. Most of those killed were police officers. Other victims include prison officers, civilians and gang members. Sao Paolo has witnessed violence of this kind before but rarely on this scale.