Works Minister Samy Vellu said the failure to take immediate action on several minor landslides could have led to the collapse of a hill slope in Hulu Klang which claimed four lives last Wednesday.

He said early reports by the Hillslope Engineering Division of the Public Works Department (PWD) indicated that the minor landslides were not repaired, according to a Bernama report.

"A reinforced earth wall was built on weak zone and the base was not socketed into the hard ground," he told reporters in Petaling Jaya today..

Plastic sheets used to cover the minor landslides were also recovered during a PWD probe.

Unstable soil

The minister called for all new development projects in Hulu Klang and its surrounding areas to be reviewed because there were signs that the soil on the hill slopes was not stable.

Occupants of houses along Jalan Timur in Taman Zoo View on the hill above the landslide area should also be vacated due to the unstable soil conditions, he said.

"Tension cracks along the hillslope close to where the landslide occurred must be covered with thick or heavy duty plastic sheets," he added.

The minister said PWD would conduct a thorough investigation of the incident and present a report to the government within a month.