Andrew Pochter was in Egypt to teach English to children

understanding,” the post read. “As we understand it, he was witnessing the protest as a bystander and was stabbed by a protester.”

Pochter was stabbed in the chest during a protest in the coastal city of Alexandria, where anti-government demonstrators stormed an office of the ruling Muslim Brotherhood. It was not clear why he was there, but Egyptian officials said he was carrying a small camera.

Obama said: “We’d like to see the opposition and President Mursi engage in a more constructive conversation about how they move their country forward because nobody is benefiting from the current stalemate.”

Hundreds have been wounded and at least eight killed in street fighting which has lasted more than a week as political deadlock deepens. Also on Friday, a bomb killed a protester at a rally by the Suez Canal.

The US ambassador in Egypt has angered liberals by saying Mursi was legitimately elected and that protests may be counter-productive for an economy crippled by unrest that has cut tourism revenues.

Mursi’s critics hope millions will march today, when he marks a year in power, to demand new elections. They accuse his Muslim Brotherhood of hijacking the revolution of 2011 and using its electoral majorities to monopolise power.

The Egyptian army, heavily funded by Washington since before Hosni Mubarak was overthrown, is on alert. It warned politicians it may step in if they lose control of the streets – an outcome some in the diffuse opposition coalition may welcome, but which Mursi’s Islamist allies might respond to with force.

In Tahrir Square in Cairo, seat of the uprising of early 2011, flags and tents indicated a base camp for protesters. They hope to see millions of people on the streets.

“Mursi is no longer the legitimate president of Egypt,” said Mohamed Abdelaziz, a protest organiser.