All of Rio de Janeiro's places of public entertainment will be required to search patrons with metal detectors under a new law expected to go into effect on Wednesday.

Under the law drafted by city councillor Ruy Cezar, nightclubs, cinemas, theatres and dance halls that fail to fit metal detectors will be fined the equivalent of $150 and could be shut down.

The mayor of Brazil's sceiond largest city, Luiz Paulo Conde, vetoed the law last year claiming the cost of metal detectors could drive some establishments out of business. The veto was overturned last week.

Mr Cezar, who proposed the law in 1997 after a man was shot and killed leaving a night club in Rio, argued that metal detectors were available for as little as $56.

"If everybody were thinking about how to control violence in their limited areas we could have a crime-free Rio," Mr Cezar said.

Sao Paulo shooting

A shooting in which three died and five were injured last November, carried out by a 24-year-old student at a cinema in Sao Paulo, gave the law some momentum.

The mayor could still annul the law by declaring it unconstitutional.

Some theatre owners are also opposed to the law.

"We've got to be sensible about this or people are going to have to go through metal detectors just to go to a newspaper stand," cinema owner Nelson Krumholz said.

"I don't think people will enjoy being searched as they are walking into the theatre," said Rosali Finkielsztejn who runs three theatres in the city.