Thomas Cook, one of Europe's biggest tour operators, announced Friday it was pulling out more than 4,000 tourists from Tunisia as the political unrest in the north African country worsened.
Around 2,000 German holidaymakers were being repatriated, while a further 1,800 from Britain and Ireland were being flown home and 540 were returning to Belgium.
Other tour firms said they were not evacuating customers but were giving them the option of coming home early if they wanted.
Tourism plays a key role in Tunisia's economy.
"Several charter planes will be sent to Tunisia today to pick up around 2,000 German clients of Thomas Cook," the German unit of the British company said in a statement.
All its departing flights to Tunisia have been cancelled until Monday and the holidaymakers offered alternative destinations.
The company said it would allow its customers to change their travel plans at no cost until January 24.
Violent unrest against President Zine El Abidine Ben Ali's iron-fisted rule has plagued the popular holiday destination since mid-December in the worst political violence in his 23 years in power.
One Thomas Cook flight has already returned 180 tourists to Brussels, with two further flights scheduled Friday.
Thomas Cook's Britain and Ireland branch said they had scheduled six repatriation flights Friday from the resort of Monastir - two to London Gatwick Airport and four to Manchester in northwest England.
"Although there has been no specific problems for our holidaymakers, their well-being is our primary concern so, as a precaution, we've taken the decision to bring them back to the UK as soon as we can," a spokeswoman said.
Thomas Cook cancelled its next departures from Britain to Tunisia, due out on Sunday.
"We are currently reviewing the situation for the next departures which are planned for Wednesday," the tour operator added.
Britain's Foreign Office said it was advising "against all but essential travel to Tunisia".
"The situation is unpredictable and there is the potential for violence to flare up, raising the risk of getting caught up in demonstrations," it said.
Approximately 400,000 tourists from Britain visit Tunisia annually.
The Association of British Travel Agents said it thought around 5,000 British tourists were currently in Tunisia.
Travel firm TUI, which owns operators Thomson and First Choice, said Friday it would not repatriate its 1,000 German customers currently in Tunisia.
"The atmosphere among our clients is calm. We have not had any requests until now for an early return," it said in a statement.
The British arm said they were giving customers the option to return home early if they wanted, though only a minority of its 1,500 holidaymakers in Tunisia had registered an interest.
"Should the situation change, we will of course take immediate action and update customers," a spokeswoman said.
Four of its Sunday flights to Monastir - from London Gatwick, Manchester, Glasgow and East Midlands - have been cancelled due to the Foreign Office advice against all but essential travel.
Germany, the Netherlands and Portugal have given similar warnings.