RIO DE JANEIRO (AP) — A 76-year-old woman and her daughter were killed Friday during a shootout between police and drug traffickers in a Rio de Janeiro slum, apparently hit by stray bullets.

Marlene Maria da Conceicao was shot in the neck in the doorway of her home in the Mangueira slum. Neighbors told The Associated Press that her 42-year-old daughter, Ana Cristina da Conceicao, was hit when she tried to help her mother.

After the deaths, residents began protesting, blocking roads and burning a bus.

Military police were conducting an operation when the firefight began. It wasn't immediately clear whether the stray bullets came from shots by police or traffickers.

Violence has been on the rise in Rio's hundreds of slums amid an economic crisis in recent years.