BEIJING - China is improving its seismic early warning system to issue alerts five to ten seconds after tremors occur, an official with the national monitoring center said Tuesday.

Fast early warning systems are being tried out in Beijing, Sichuan and Guangdong with more monitoring stations, said Pan Huaiwen, head of the China Earthquake Networks Center (CENC).

May 12 is China's national day of disaster prevention and relief, established in 2009 to recall the 2008 Wenchuan earthquake that killed more than 80,000 people.

China's national earthquake monitoring network, composed of the CENC, 32 regional monitoring centers and 1,098 observation stations, leads the world, Pan said.

These centers can monitor quakes as slight as magnitude one, and preliminary monitoring results can be automatically released about one minute after the quake occurs. However, the ability to forecast earthquakes is still weak, Pan admitted, adding it is a global challenge.

To forecast strong quakes in 10 years and magnitude six quakes in two years is "comparatively" accurate. Imminent quakes, in three months, can hardly be forecast at all, Pan said.

He said China had forecast more than 30 short-term or imminent quakes, including a 7.3-magnitude earthquake in northeastern Liaoning province in 1975, helping reduce damage.