Activists trying to oust Egyptian President Hosni Mubarak played cat-and-mouse with police on the streets, as unprecedented protests against his 30-year rule entered a third day.

Prominent reform campaigner Mohamed ElBaradei, who lives in Vienna, was expected to return to Egypt, an arrival that could galvanise protests that so far have lacked a leader.

At least three protesters and one policeman have died in clashes since they erupted on Tuesday. The protests were inspired by a popular revolt in Tunisia and are unprecedented during Mubarak's strong-handed rule.

Police have fired rubber bullets and tear gas at demonstrators throwing rocks and petrol bombs.

In central Cairo, demonstrators burned tyres and hurled stones at police. In Suez, protesters torched a government building.

Demonstrations continued well into the night. By the early hours of Thursday, smaller groups of protesters were still assembling in both cities and being chased off by police.