At least 13 killed in shooting at school for kids aged 10-15 in Rio de Janeiro

At least 13 people have died after a gunman opened fire in a school in western Rio de Janeiro.

Some 20 people, including children, were wounded in the shooting at the school for students aged 10 to 15, the Associated Press reported.

The vice-mayor of western Rio said 13 people had died in the shooting at Tasso da Silveira school, although it was not clear if that figure was accurate or included the attacker.

Edmar Teixeira said the gunman was a 24-year-old former student who pretended to be giving a speech to students before opening fire with two handguns. When police appeared at the scene the gunman shot himself dead, Teixeira said. He left behind a letter outlining his motives, according to The Guardian.

By early afternoon, news of the shooting had spread throughout the country, shocking officials. President Dilma Rousseff became visibly emotional at an event in Brasília when she asked those present to observe a minute of silence for the "defenseless children" in Realengo.

"This type of crime is not characteristic of our country," she said. "All of us here, men and women, are united to repudiate this type of violence," New York Times quoted.