(CNN) -- Tour companies evacuated hundreds of vacationers from Kenya after various nations issued travel alerts that warned of a "high threat" of terrorist attacks.
All-inclusive tour company First Choice and Thomson Airways said they were canceling trips to the coastal area of Mombasa until the end of October.
They transported about 200 vacationers to London on Friday morning. By the end of evacuations Friday night, both said they expect all their 400 vacationers to be out.
"As a precautionary measure, we have also taken the decision to repatriate all customers currently on holiday in Kenya, including our air fare passengers back to the UK on Thursday and Friday," Thomson said in a statement.
A day before the evacuations, the UK Foreign Office advised against nonessential travel to various areas, including the Mombasa coastal region. It urged tourists with nonessential travel to leave.
"There is a high threat from terrorism, including kidnapping ... from extremists linked to Al-Shabaab, a militant group that has carried out attacks in response to Kenya's military intervention in Somalia," the UK alert said.
The United States also updated its travel warning this week, citing the potential for terrorist attacks in Nairobi and the coastal cities of Mombasa and Diani. Australia also urged its nationals to reconsider travel to those areas.
Kenyan authorities described the warnings as "unfriendly acts" and said security remains a top priority.
"Issuance of such travel advisories only plays to ... spread fear and panic," the Kenyan Foreign Ministry said in a statement.
The Kenyan military crossed into Somalia in 2011 to battle the terrorist group Al-Shabaab, which it blamed for kidnapping tourists in the coastal region. In retaliation, the terrorist group has launched a spate of attacks, including targeting bustling bus stations with grenades.
Last year, militants stormed the Westgate Mall in Nairobi and held shoppers under siege for days. At least 67 people were killed.
There are about 5,000 British nationals living along the Kenyan coast, according to the Foreign Office.
About 10% of those are in Mombasa and surrounding areas.