But the students, at al-Azhar, Halwan and Ain Shams in Greater Cairo and at Kafr al-Shaikh in the Nile Delta, did not leave campus - a step which often leads to direct confrontation with riot police.

Students affiliated with the Muslim Brotherhood movement said in a statement they also demonstrated on Tuesday at the university in the Nile Delta town of al-Mansura.

On Monday, several hundred students demonstrated at the elite American University in downtown Cairo, rejecting a fifth six-year term for President Husni Mubarak or any attempt to install his son Jamal in his place.
   

Husni Mubarak has ruled Egypt
for 24 years

The Muslim Brotherhood students said they were launching a campaign under the slogan "Arise, Egyptians, freedom calls you", and had already organised protests on eight campuses in the last three days.

They said their aim was to end emergency law, in force since Mubarak took office in 1981, and make sure that a constitutional amendment allows real multi-candidate presidential elections.
   
Mubarak has proposed changing the constitution to abolish the old system of a referendum on a single candidate chosen in advance by parliament, which is dominated by the ruling party.

But opposition politicians say they are worried the ruling party will make the conditions for standing so restrictive that Mubarak would not face a serious challenge in the elections, which are expected in September.