Rescuers are struggling to search five workers trapped after a railway tunnel under construction collapsed on Sunday morning in east China's Jiangsu Province, local authorities said.

Part of the tunnel collapsed at 3:25 AM when 23 people were working at the construction site at the Tingzishan Hill in the Pukou District in Nanjing, capital of Jiangsu Province. 18 managed to escape, according to the local government.

The 1,635-meter-long tunnel is part of the railway being built to link Nanjing and Hefei, capital of east China's Anhui Province.

(Xinhua News Agency September 3, 2007)