BEIJING, Dec. 22 (Xinhua) -- Security and fire safety at 992 key national cultural relic preservation units were improved with the financial support of the central government in 2017, Yue Zhiyong, an official with the State Administration of Cultural Heritage, said Friday.

The financial support approached 2 billion yuan (304 million U.S. dollars), three times the previous year, said Yue.

Yue said 730 million yuan went to 361 security projects, 1 billion yuan to fire safety projects, and 220 million yuan to 183 projects to protect against damage from lightning.

Five fires hit key cultural relics preservation units in the country in 2017, the same number as in 2016, said Yue.

The country strengthened safety of some key cultural relics in 2017, including the Great Wall, the Grand Canal, the Potala Palace and the Mogao Grottoes.