RIO DE JANEIRO - Brazil's Senate President Jose Sarney on Monday called for another referendum on gun control after a school massacre killed 12 children on Thursday.

Related readings:  Brazil reels from school shooting  12 children killed in Brazil school shooting

Sarney said he would propose a bill for a new referendum to be held as soon as possible. Last week, he called for "zero tolerance" for guns in Brazil.

In 2003, Brazil approved the Disarmament Statute, which foresaw a referendum on guns. In a referendum in 2005, about two-thirds of Brazilians voted against gun possession and sales in the country.

The massacre in a Rio de Janeiro public school, however, rekindled the debate in Brazil, with several groups calling for tighter gun control.

In one of the worst shooting sprees in Brazil, Wellington Menezes de Oliveira, 23, gunned down at least 12 students on Thursday in a public school in Rio's western region before he shot himself.

Four days after the massacre, 10 children who were injured in the shooting still remain in hospital, two of them with grave wounds.