Security experts hired to investigate and plug the breach found that the attacks used tactics similar to ones used in previous hacking incidents traced to China, the report said.

WSJ: New York Times Says Chinese Hacked Paper's Computers

The Colombian army has been involved in efforts to try to plug the 200m-wide (650ft) breach.

BBC: Colombia flooding continues with thousands homeless

"There is way too many fricking ... cooks in the kitchen, " Nagin said in a phone interview with WAPT-TV in Jackson, Mississippi, fuming over what he said were scuttled plans to plug a 200-yard breach near the 17th Street Canal, allowing Lake Pontchartrain to spill into the central business district.

CNN: Mayor blasts failure to patch levee breaches