More than 250 North African immigrants seeking political asylum in Greece began a hunger strike on Tuesday after occupying a university campus in central Athens.
The immigrants, who have been employed in menial jobs on the southern Mediterranean island of Crete, arrived at the port of Pireaus in the early hours on Sunday and then occupied the first floor of the Law Faculty in central Athens on Monday.
Another 50 immigrants headed to the northern port city of Thessaloniki to carry out a similar protest there.
The dean of the Law Faculty closed the central Athens building until at least Friday.
In a separate incident, seven Afghan refugees sewed their mouths shut to protest at the slow pace with which their asylum applications were being processed by the Greek authorities.