BOGOTA, Colombia (AP):

Colombia's coca crop - the basis for cocaine - grew by 27 per cent last year, the United Nations reported yesterday, calling the increase "a surprise and a shock", given major US-funded eradication efforts.

Eradication of the crop in Colombia, the world's No. 1 cocaine-producing nation, has been the cornerstone of a multibillion-dollar US aid package.

Coca cultivation was also up four per cent in Peru and five per cent in Bolivia, the UN Office on Drugs and Crime (UNODC) reported in its annual survey.

It estimated cocaine production in the Andean region was stable, however, at about 994 metric tons, compared to 984 metric tons in 2006.

Colombian cocaine production failed to keep pace with coca planting because police pressure forced an interruption in the growing cycle, Gen. Oscar Naranjo, chief of Colombia's police, told reporters.

"These young crops, the new ones, are less productive," Naranjo told a press conference in Bogota.

He said that eradication pro-grammes also are pushing coca farmers to more remote areas where it is harder to obtain the chemicals needed to make cocaine.

"The increase in coca cultivation in Colombia is a surprise and shock: a surprise because it comes at a time when the Colombian government is trying so hard to eradicate coca; a shock because of the magnitude of cultivation," the UNODC's executive director, Antonio Maria Costa, said in a statement.

Heavy Taliban presence

He noted, however, that almost half of Colombia's coca comes from just 10 of the country's 195 municipalities. "Just like in Afghanistan, where most opium is grown in provinces with a heavy Taliban presence, in Colombia most coca is grown in areas controlled by insurgents."

In all, 99,000 hectares, or 382 square miles, of coca cultivation were found in Colombia last year, up from 78,000 hectares in 2006, the UN said. It estimated total cultivation last year in Colombia, Peru and Bolivia, the world's three principal sources of coca, at 181,600 hectares, or 701 square miles.