Soldiers were searching mud and debris Friday for any additional victims of a massive landslide that buried a highway in central Mexico and left at least four dead -- following another mudslide that killed 10 elsewhere.

A mountainside collapsed Thursday in eastern Mexico, slamming into a tractor trailer, a pickup and several public buses. The battered, dirt-caked carcasses of the vehicles were scattered in a mud field on the edge of a lake.

Officials said one of the dead included a woman whose backpack contained several baby bottles, prompting rescue workers to search for an infant among the debris.

The landslide occurred on a highway between Mexico City and the city of Tuxpan. Four people died and at least 11 others were injured, Puebla's interior secretary, Javier Lopez Avala, told a news conference late Thursday that was broadcast live on the radio.

It was not clear exactly what caused the landslide.

CountryWatch: Mexico

Lopez Avala said workers had been using heavy machinery on the site recently to extract gravel, which weakened the hillside that collapsed. Heavy rains have pounded that part of the country in recent weeks as well.

Heavy rains triggered another landslide that killed 10 people, mostly children, and injured three others late Wednesday in the remote, Indian village of Chalchihuitillo, 450 miles northwest of Mexico City, Serenia Moreno, a spokeswoman for local authorities said by telephone.

Five members of one family -- including a man, his wife and three children, ages 5 to 9 -- were killed after an avalanche of mud and rocks buried their home. Five children, ages 5 months to 7 years, were killed in four other homes, the spokeswoman said.

An injured woman, teenage girl and infant boy were taken to a hospital for treatment, Moreno said.

Moreno said authorities didn't know how many people were in the homes and rescue crews were still digging through the mud in search of other possible victims.

The homes, in Durango state, were at the foot of a mountain that gave way after strong rain storms.

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