A member of Israeli General Staff Reconnaissance Unit, Sayeret Matkal, has been arrested in Egypt amid massive anti-government protests.

The unnamed official was detained on Thursday as Egyptian protesters are keeping up the pressure on President Hosni Mubarak to step down, a Press TV correspondent reported.

Millions of people have gathered in Cairo's Tahrir Square, which has been a focal point for demonstrators, as well as elsewhere for the tenth consecutive day and chanted anti-government slogans.

On Tuesday, Mubarak announced in a televised address that he will not run for a sixth six-year term of office. However, he refused to relinquish power.

"I will use the remaining months of my term in office to fill the people's demands," he said.

Protesters resumed their "Leave, Mubarak!" chant in downtown Cairo following the 82-year-old Egyptian president's address.

Clashes also broke out between demonstrators and security forces in the Mediterranean city of Alexandria shortly after Mubarak's announcement.

Egyptian opposition groups are calling for departure of Mubarak from power, the formation of a new parliament, and amendments to the constitution.

As many as 300 people may have been killed, and thousands injured, in clashes between security forces and protesters in Cairo and other Egyptian cities over the past week.

"Casualties have been mounting on a daily basis, with unconfirmed reports suggesting as many as 300 people may have been killed," UN High Commissioner for Human Rights Navi Pillay said on Tuesday.

Egypt's main opposition movement, the Muslim Brotherhood, has condemned the United Nations and Western countries for not attempting to stop the government's use of excessive force against protesters.

The revolution in Egypt follows a historic one in Tunisia, which forced President Zine El Abidine Ben Ali to give up power and flee after 23 years of authoritarian rule.