Several vehicles were believed to have been trapped yesterday under a massive landslide on Costa Rica's Inter-American Highway near the exit for Chomes, Puntarenas, which is near the turn-off for the popular north-central mountain reserve of Monteverde, the Red Cross said.

Mud and rocks came falling down from the side of the road at 1:30 p.m., said David Picado, of Red Cross' disaster prevention unit. He said reports to the Red Cross said at least three vehicles were trapped, but the number could not be verified yet as workers raced to dig through the wet rubble.

The highway, a major route from the capital to the Pacific port of Puntarenas and Liberia airport and seaside resorts of the northwestern province of Guanacaste, remained closed by evening yesterday.

Weeklong rains, overflowing rivers and flooding have killed at least three people – two in the central Pacific region and one near the north-central region of Monteverde – and forced some 2,100 residents into 37 shelters across Costa Rica, with increased relief efforts in Guanacaste, the central Pacific towns of Parrita and Quepos and the northern canton of Upala, the National Emergency Commission and Red Cross reported.

About 30 cantons from north to south remained on red alert.

The emergency authorities said to take caution driving, particularly across bridges over rivers that are swelling in the rainstorm.

Analysts at the National Meteorological Institute forecast rains could begin to let up tomorrow.