Switzerland on Friday announced a closure of its airspace as a preventive measure as a cloud of volcanic ash from Iceland approaches the country, the official Swissinfo.ch news website reported.

The ban will begin at midnight, when the ash is expected to arrive over Switzerland, and remain in force until Saturday morning, the civil aviation office was quoted by the website as saying.

The only planes still allowed to fly are those on search and rescue missions, it said.

The office added that it was monitoring the situation closely and would decide later whether to extend the ban.

Switzerland is one of many countries in Europe which have closed their airspace as the cloud moves south and east. Hundreds of thousands of passengers are already stranded throughout the continent due to the cancellation of flights to affected countries, according to the report.

The measure was taken after the volcano under the Eyjafjallajokull glacier started spewing ash high into the atmosphere on Wednesday.