Jet2, which flies from Leeds-Bradford to Sharm el Sheikh, was sticking to its schedules last night and British Airways and the Foreign Office said the main resorts seemed to be calm.
But their assurances were hedged with caution as Tui, the parent company of Thompson and First Choice, said it had cancelled several flights to Egypt on Foreign Office advice.
Flights to resorts such as Sharm el Sheikh, Hurghada and Marsa Alam were not affected by the demonstrations and Tui said its services would still operate to and from the resorts.
The tour operator said it had 11,000 customers in Egypt including 8,700 in Sharm el Sheikh and 950 in Luxor.
Crowds filled the Cairo's airport as people desperately sought to leave.
Foreign Secretary William Hague said Britons should get out of the major cities of Cairo, Alexandria and Suez if they could. US citizens are also being advised to leave.
Gangs of armed men were said to have attacked four prisons freeing thousands of inmates including key activists in the influential but outlawed Muslim Brotherhood. Looters and robbers took advantage of a melting away of the police presence in Cairo, with only citizen vigilantes to stop them.
Mr Hague warned that Egypt was in danger of falling into the hands of extremists.
Prime Minister David Cameron had earlier put together a joint statement with French President Nicolas Sarkozy and German Chancellor Angela Merkel saying: "The Egyptian people have legitimate grievances. We urge President Mubarak to embark on a process of transformation which should be reflected in a broad-based government and free and fair elections."
Mr Hague said Egypt was a "sovereign nation" and Britain was not trying to "pick who should be president".
But he said: "What matters is that the process takes place, whatever that means for President Mubarak personally. That is far preferable to Egypt falling into the hands of extremism or a more authoritarian system of government."
US Secretary of State Hillary Clinton said: "We want to see an orderly transition so that no-one fills a void, that there not be a void, that there be a well thought-out plan that will bring about a democratic participatory government."
There were questions yesterday over whether Mr Mubarak still commanded the loyalty of the military, who had appeared unwilling to quell the uprising with force. But last night there were signs the crackdown was coming, with troops and armoured vehicles moving into the cities in numbers and jets flying low over the main square in the capital. Police were also returning to some streets.
It was reported some of the president's family had fled the country and an official at Cairo airport said 19 private jets had left, carrying families from the business elite.
Observers were stunned by the pace of events since Tunisia toppled its president earlier this month and were speculating about where the Arab world would crumble next. Protests have already been held in Yemen, Algeria and Jordan.
Mr Mubarak failed to calm his country with a government reshuffle on Friday night and promises of new jobs on Saturday. Half his people have been living on less than 1.30 a day. And half of the 18 million people in Cairo are under 30. Protesters said they wanted the complete removal of an administration they blame for poverty, unemployment, corruption and police brutality.
In Tahrir Square, in the heart of Cairo, schoolteacher Hussein Riyad said: "People have been suffering for 30 years. A few days of horror don't matter."
Lines of army tanks jammed a road leading into Tahrir, and a military helicopter hovered overhead.