At least four road construction workers were killed and at least 50 others injured yesterday in a massive landslide, triggered by heavy rain in Kangding county of the Garze Tibetan autonomous prefecture in Sichuan province.

Authorities launched a State-level emergency response system and task force yesterday evening to help deal with the disaster, an official with the Ministry of Civil Affairs said.

Rescuers saved 97 workers trapped at the site, where a landslide-formed lake holding about 3 million cu m of water and mud had already formed to threaten the area, authorities said.