South Sudanese rebels have released 18 United Nations peacekeepers who were on board a barge that was seized on the river Nile earlier this week, a UN spokeswoman said Friday. According to dpa, they were released on Thursday, said Ariane Quentier, a spokeswoman for the UN mission in South Sudan. She declined to reveal their nationalities. The rebels also captured 12 South Sudanese contractors who had been on board. Quentier denied reports that they had been released. The rebels still held the contractors, weapons they had taken from the peacekeepers, the vessel and its cargo of fuel, the UN mission said in a press release. Seizing the vessel "is an attack against the peacekeepers which can be considered a war crime," Quentier said.