Mohamed Areski Himeur
The authorities in Algeria have deployed more than 1,000 soldiers, gendarmes and border guards in the search for tourists who have gone missing in the Sahara desert over the last few months.
The push to find them follows pressure from the German government, which is anxious to locate 18 German nationals who have disappeared in the region.
Germany is helping in the search
The others include eight Austrians, four Swiss nationals, one Dutch national and one Swede.
They made up six separate tour groups which all went missing as they crossed from Tunisia into the Algerian Sahara.
Two helicopters and a reconnaissance plane equipped with thermal detection instruments are criss-crossing the search area between Ouargla , Djanet and Tamanrasset, three or four times a day.
Guides known as "bloodhounds of the desert" are also taking part in the search.
German anti- terrorist unit
Units of frontier guards, companies of gendarmes, and units of the National Army, totalling 1200, all supported by experienced guides, are out searching.
The search operation was stepped up following a visit to Algeria earlier this week by German Interior Minister Otto Schily, who was looking at efforts being made to find the German tourists.
Five agents from the German anti-terrorist police have been rushed to Algeria to take part in the operation.
Berlin is said to be very worried by the disappearance of their nationals.
In Algeria, three theories on how the tourists disappeared have been advanced.
They lost their way in the immense desert which extends for some 2m square kms.
They were kidnapped by smugglers operating along Algeria's borders with other countries, notably Niger, Mali and Libya.
They were abducted by Islamic extremists.
This last theory seems more and more likely as the days pass with no trace of the missing tourists.