Palestinians permitted to cross may hold Jerusalem ID papers, foreign passports or they may have obtained permission from the Israeli military authorities.

Palestinians who do not have the necessary papers often try to cross illegally into Israeli areas to find work, taking routes avoiding checkpoints. Many are caught and returned.

Allegations of verbal and physical abuse by Israeli soldiers and border guards, such as the case on the right, are common. The Israeli army says these are taken extremely seriously and that formal complaints are examined through military police investigations. A spokesman told BBC News Online that a few claims have proved to be valid, but these are exceptions.

Some checkpoints have metal detectors. These have cut down the need for manual searches of Palestinians, which are carried out in an attempt to stop militants carrying firearms or explosives from entering Israel.

Soldiers at other checkpoints conduct manual searches – usually on young men thought most likely to fit the profile of a suicide bomber.