The St. Louis area in the US state of Missouri is facing a weekend of possible racial unrest after an off-duty St. Louis police officer shot and killed a black teenager on Wednesday night.

The incident has further fueled anger in the region in the wake of the August 9 police shooting in the nearby suburb of Ferguson of the black unarmed teenager Michael Brown.

St. Louis Police Chief Sam Dotson said the officer, who was working for a private security company when Wednesday's shooting took place in the St. Louis neighborhood of Shaw, had shot at the 18-year-old in self-defense after the teen opened fire on him.

People saying they were relatives of the dead teen, however, told the St. Louis Post-Dispatch that he did not possess a gun. They identified him as Vonderrit Myers Jr..

The killing triggered an angry demonstration, with many in the crowd drawing comparisons with the shooting of Brown, whose death led to weeks of violence in Ferguson. Police said several police cars were damaged in the Shaw protest.

Remembrance marches

The shooting comes after several civil rights organizations and protest groups announced plans to hold marches and rallies in St. Louis and Ferguson on the weekend to mark two months since Brown's death.

The groups are calling for the arrest of the officer who killed Brown, while also aiming to highlight concerns at police treatment of Afro-Americans.

Although the groups have said their protests will be peaceful, police fear that Wednesday's killing could trigger violence.

Ferguson Mayor James Knowles said police were planning for large crowds and possible violent incidents. Knowles said that many people were coming to the suburb from outside to take part in the weekend's events, and that there had been information that some wanted to cause trouble.

The suburb of Ferguson has 21,000 residents, most of them African-American, with an overwhelmingly white police force and town government.

tj/sb (AFP, Reuters, AP)