The violence took place Tuesday in a city in the oil-rich country's southwest amid a nationwide strike over high fuel prices.
Red Cross spokesman Nwakpa O. Nwakpa said the attack occurred in Benin City, where an angry mob tried to burn down a mosque the day before. Nwakpa said there were casualties in the attack Tuesday, but said he had no further details.
The nationwide strike started Monday by labour unions upset over high fuel prices in this oil-rich nation. Gas prices have more than doubled since the subsidy on fuel ended Jan. 1 at the orders of President Goodluck Jonathan's administration.