The Ministry of Education demanded "immediate" action on Wednesday to ensure school classrooms are warm enough after media reports said a delayed heating supply in Hebei province resulted in students showing symptoms of frostbite.

China Youth Daily reported on Tuesday that the heating supply in some rural primary schools in Hebei's Quyang county has been delayed, forcing students to attend classes outside in the sun in a bid to keep warm.

Some primary school students were seen standing up reading books and others kneeling or sitting on the ground, using stools as desks, in a China Youth Daily video.

"We felt sorry for the children after reading the report and were worried about them," ministry spokeswoman Xu Mei said at a news conference in Beijing.

She said the ministry attaches great importance to the issue, and senior officials have demanded "practical" and "efficient" measures to urge local authorities to provide heating in these schools immediately.

The State Council's Office of Education Steering Committee has handed notifications to relevant provinces to supervise the handling of the issue and demanded these provinces ensure normal school services, she said.

"When it comes to children, nothing is trivial," she said.

The publicity department of the Quyang government said on Wednesday that heating had been supplied to students from 11 rural schools as promised by Quyang Party chief Wang Peng.

The delay in the heating supply occurred because some schools failed to transform coal-fueled heating facilities to electricity-fueled ones on time, which is part of a campaign to replace coal with clean energy as a heat source in the province.

Coal has long been burned for heating in northern China, but it is blamed for smog in winter. Hebei vowed in September last year to ban bulk coal consumption in 18 counties adjacent to Beijing by the end of this year.