Operators and agents have been working around the clock to ensure their customers are safe following a 6.3-magnitude earthquake that devastated Christchurch on Tuesday.

A state of emergency was declared in the country as the death toll rose to 75 and 300 people were still missing.

Hotels have been evacuated in the centre of the city. Some hotel companies are reported to have moved travellers to properties in other parts of the South Island. Some tourists are understood to have left behind their travel documents as they fled.

One of the city’s tallest buildings, the hotel Grand Chancellor, is on the verge of collapse, reports claimed. Opposition leader Phil Goff told local press: “It’s 26 storeys high, there’s a big bend in the building, it’s going to come down. People staying in that hotel will lose their possessions.”

STA Travel and sub-brand Bridge the World had just under 1,000 customers in the Christchurch region when the earthquake struck. UK operations director Kate Howard said: “All customers who were in the heart of Christchurch were evacuated and are safe. We have not yet been able to make contact with all of them to confirm their onward travel plans.”

STA’s customer service teams were using social media to contact customers, as well as email. She added: “We are using as many routes as possible to communicate at this extremely worrying time.”

As Travel Weekly went to press the Foreign and Commonwealth Office was urgently seeking information about any UK casualties, but it was not yet known if any British travellers were among the dead.