Kabul, Afghanistan ? Afghanistan’s world-leading opium cultivation rose a “staggering” 59 percent this year, the U.N. anti-drugs chief announced Saturday in urging the government to crack down on big traffickers and remove corrupt officials and police.

The record crop yielded 6,100 tons of opium, or enough to make 610 tons of heroin – outstripping the demand of the world’s heroin users by a third, according to U.N. figures.

The bulk of the opium increase was in lawless Helmand province, where cultivation rose 162 percent and accounted for 42 percent of the Afghan crop. The province has been wracked by the surge in attacks by Taliban-led militants that has produced the worst fighting in five years.