More than 500 people signed up to buy state-vetted cannabis in Uruguay on the first day of registration for the first such scheme in the world, authorities said Wednesday.

The state launched the register on Tuesday to log users who will be able to buy 10 grams of the drug a week in pharmacies for recreational use from early July.

The state Cannabis Regulation and Control Institute said on its website that 568 people had signed up so far in the South American nation of 3.4 million inhabitants.

That added to more than 6,600 registered growers and 51 authorized smokers' clubs which already existed under earlier stages of a 2013 law.

The legislation is the first in the world to legalize and regulate the production, sale and consumption of for recreational use.

The weed is grown by two in state-regulated farms near the capital, Montevideo.

A gram of pot will cost $1.30 to buy in a pharmacy, the secretary general of the National Drugs Council, Diego Olivera, said last month.

Some lawmakers still oppose the law to legalize marijuana, passed under the colorful leftist former president Jose Mujica.

A poll at the time indicated that nearly two thirds of Uruguayans opposed it.

The government says the law will help curb the violence and crime of the trade.