The self-styled “freedom marchers” include prominent authors, lawyers and journalists, many of them Jewish.
They had hoped to cross the border to Gaza for a planned protest today against Israel and its economic blockade of the area, but they too have fallen victim to the blockade.
When the peace activists arrived in Cairo, the Egyptian government all but banned them from travelling even to the Egyptian side of the Gaza border.
Two days ago, Egyptian police detained one group of protesters who had managed to cross the Sinai Desert and effectively placed them under house arrest on the grounds the march was illegal and the situation in Gaza was too sensitive.
Another group of protesters, who had sought the support of the American embassy, say they too were detained and harassed.
So in recent days the protesters in Cairo have directed as much of their anger at Egypt, for its apparent complicity with the Israeli blockade.
Many of the 1,300 peace marchers staged a sit-in outside the United Nations building to enlist the UN’s support against Egypt.
One Australian taking part is Jewish author and journalist, Antony Loewenstein. He says the trip to Gaza will not be seen as a failure should the activists not get in.
“Not getting into Gaza doesn’t really negate the importance of the trip itself,” he said.
“What we’re trying to do, whether we get into Gaza or whether we simply stay in Egypt, is to make a very strong statement about the suffering of the people in Gaza itself.
“It’s important for people to remember that when there was a war there a year ago, all the buildings that were destroyed, the infrastructure, the sewerage plant, none of that has been rebuilt and until that changes there is legitimate protest to be made.”
However, after the last-minute intervention of President Hosni Mubarak’s wife, Egypt has agreed to let two busloads of protesters through the border at Rafah to take part in today’s protest in Gaza.
One of them is Australian peace activist Donna Mulhearn.
“Around about 50,000 people from Gaza are ready to be marching along with those internationals who are able to get through, so we hope that that will draw some attention,” she said.
A separate convoy of humanitarian workers carrying medical aid for Gaza is also stranded in Jordan, because Egypt has banned them from travelling to Gaza via the Red Sea.
Egypt is demanding they go all the way back through Jordan and Syria, and take a Mediterranean route closer to the Gaza border.
In the end though, no amount of protests or pressure is likely to bring an end to the Israeli blockade, which bans the movement of people from Gaza and the import of all but the most essential supplies.
The Israeli government imposed the blockade two years ago after Hamas came to power and says it was meant to target the Islamist regime and not Gaza’s civilian population.