LISBON (Reuters) - A dozen protesters were arrested and several injured during an anti-government youth rally in the Angolan capital Luanda Saturday, according to media reports, with authorities saying four police officers were also injured. The rally, organized by a youth movement without the support of any of the main opposition parties, called for the resignation of President Jose Eduardo dos Santos, who has held power in oil-rich Angola for over 32 years. According to the Portuguese television station RTP, around 200 youths gathered at Luanda's Independence Square at 1200 GMT.