Over recent weeks news reports have covered war crimes in different parts of the world that are beset by conflict. War crimes are considered to be among the most serious international crimes. But what is a war crime?
Brazil has deployed 5,000 troops to its beaches amid mounting fury at the government's inaction over the worst oil spill in the country's history.
The environmental catastrophe began in early September when large quantities of oil inexplicably washed ashore.
The mysterious spill has continued and has now touched more than 1,000 miles of Brazil's coast, polluting some of the country's most picturesque beaches and destroying local marine life.
Now public anger is rising over the Brazilian government's failure to stem the flow - or indeed establish the oil's source. In response, local officials have resorted to urging volunteers to aid the cleanup mission.