More than 50,000 hectares of farmland in North Korea's granary zones have been damaged by drought, a US broadcaster reported Tuesday, citing UN data. 

According to the UN Office for the Coordination of Humanitarian Affairs, a spell of dry weather has continued in the North's main agricultural land as the precipitation there dropped by 30-80 percent in January, compared with that in previous years, Radio Free Asia said.

"The yield in Pyongan and Hwanghae Provinces and Nampo City is expected to decline 30-80 percent this year from a year ago due to the drought in some 50,000 hectares of farmland there," the broadcaster said. 

Last Tuesday, a joint investigation, comprising officials from OCHA, North Korea and the International Federation of Red, conducted an on-site inspection in South Hwanghae Province to grasp the actual state of the drought damage, according to the broadcaster.

The drought is also deteriorating the water quality, causing concerns over the spread of waterborne diseases among North Korean people, OCHA was cited as saying.

The drought has persisted since April, it added. (Yonhap)