Geneva: New landslides have forced more evacuations from a valley in the Swiss Alps where eight hikers were buried in a barrage of boulders and mud a week ago, authorities said on Friday.

Two landslides within hours caused no injuries but destroyed houses in several villages and cut access roads into the Bregaglia valley, near the Italian border.

A violent thunderstorm and heavy rains lashing the Piz Cengalo at the Italian border set an already unstable land mass in motion, sending rocks and sludge down the mountainside late Thursday.

The river of mud followed the same path as the giant landslide that hit the area last week, when eight hikers from Germany, Austria and Switzerland disappeared.

Thursday’s landslide flowed into Bondo and neighbouring villages, destroying houses and roads in its path, municipal authorities in the Bregaglia valley said in a statement.

Early Friday, a second landslide flowed from the Maloja peak into the opposite side of the valley, cutting off a highway, it said.

Most residents in the hamlet of Spino had left on their own, but two elderly people were evacuated by emergency workers. No one was injured, the statement said.

In Bondo, where around 100 people were evacuated after last week’s landslide, several houses were completely demolished.

Houses were also destroyed in the village of Promontogno, which also lost power, and some houses were damaged in Spino.

Authorities said it appeared that the latest landslide had been quite large, though its exact size has not yet been determined.

They had warned Bregaglia residents earlier on Thursday that the heavy rains made more landslides in the region likely.

The initial landslide that hit the area on August 23 set four million cubic metres of mud and debris in motion.

The event was so severe that the vibrations set off seismometers across Switzerland, which registered the equivalent of a 3.0 magnitude earthquake, according to the Swiss Seismological Service.

Authorities have warned that up to one million cubic metres of rock and dirt remain unstable and could still come tumbling down Piz Cengalo.