CAIRO (AFP/REUTERS) - A top aide to President Mohamed Mursi of Egypt, Mr Essam al-Haddad, slammed what he called a "military coup" on Wednesday after an army ultimatum and a travel ban on the president and his Islamist allies.

"For the sake of Egypt and for historical accuracy, let's call what is happening by its real name: Military coup," Mr Haddad, President Mursi's national security adviser, said in a statement on Facebook.

As tensions mounted and crowds poured into the streets to demand Mr Mursi's resignation, Mr Haddad said: "As I write these lines I am fully aware that these may be the last lines I get to post on this page."

"In this day and age, no military coup can succeed in the face of sizeable popular force without considerable bloodshed," he added.

President Mursi's message to all Egyptians, as stated in a televised address overnight, was that they should resist the "military coup" but they should do so peacefully, without violence against troops, the police or each other, said another aide, Mr Yasser Haddara, a communications adviser.

Mr Mursi spent Wednesday working normally at a regular presidential office in a compound of the Republican Guard in suburban Cairo, he said, adding that it was unclear if the president would be free to leave later to return to the palace where he spent the previous night.

He had had no contact during Wednesday with the military high command.