The number of bloggers being arrested has increased steadily since 2003, according to the World Information Access Report by the University of Washington.

The study says that just 10 bloggers were arrested in 2006, but the number stood at 37 in 2007.

"After surveying our data, we predict that the number of blogger arrests will rise in 2008," the report says.

Egypt, China and Iran were identified as the locations of over half of the cases and according to the report most arrests take place during elections, civil unrest and other politically sensitive times.

"During the five years we researched, bloggers spent a total of 940 months in jail, while the average prison time for a blogger was 15 months," added the report. Although this was based only on reported arrests, and that the actual figure may be much higher.