About 500 people protested in Beijing against a garbage disposal plant they say has been releasing noxious fumes into the air, with two demonstrators hurt in a scuffle with security officials, a rights group said Sunday. The Hong Kong-based Information Center for Human Rights and Democracy said the protesters Saturday called for the resignation of the top environment official in Beijing's Chaoyang district, where the garbage plant is located. The demonstration was held near the plant, and a tussle between protesters and the authorities resulted in two protesters being hurt, the group said in a statement. The rights group also said one of the organizers of the protest went missing Saturday night and was presumably taken away by security officials. The Beijing Public Security Bureau's information office said Sunday that it had no information about the incident.