FRANKFURT (Reuters) – Europe’s top travel companies were monitoring the spread of bird flu in Turkey yesterday as authorities tightened security at airports in the region but said they had yet to see any major impact on their business. Even as the shares of some of the sector’s key players came under pressure, holiday firms and airlines said it was too early to quantify what – if any – impact the virus, which has killed three children in eastern Turkey in recent days, might have. «We are monitoring the situation closely and keeping in contact with the authorities,» said a spokesman for Deutsche Lufthansa, Europe’s second-biggest carrier. Turkey has now confirmed 15 people with bird flu infections since last week, most in eastern, central and northern parts of the country. More than 70 people are suspected of having the bird flu virus and are undergoing tests. «Russia has already warned against travel to Turkey and, in the face of the latest news, the worries are gradually increasing here,» said one German share trader. Four people have now been taken to the hospital with suspected bird flu near the Aegean coast, one of Turkey’s most important tourism centers, fueling fears the outbreak would harm the country’s important tourist trade. Europe’s biggest tourism company, TUI, said there was no evidence yet of any impact on its business from bird flu. «We’ve had inquiries from some holidaymakers, but no requests for changes to bookings or cancellations so far,» a TUI spokesman said. TUI saw no reason yet to change its offering in Turkey for the coming summer. Turkey was the destination for 7 percent of TUI’s customers in the tourism year through October 2005, but was not a popular winter holiday destination. A spokeswoman for British Airways also said it was too early to say what effect bird flu would have. «We’ve not seen any impact at the moment,» she said. «We are still flying to parts of Asia where bird flu has been an issue for longer.» The UK’s Foreign and Commonwealth Office said the risk of the virus spreading to humans was low. «The risk of avian flu to British nationals visiting countries affected by avian flu is believed to be very low. There is no reason not to travel to these countries,» it said on its website. Following the outbreak in Turkey, German customs authorities said they had stepped up controls of passengers and luggage at Frankfurt airport, continental Europe’s biggest hub. Coaches from Turkey, Romania, Russia and Croatia were also being checked more intensively at Frankfurt’s main bus station.