DUBAI, Dec 26 (Reuters) - Iran has banned the entry of travellers from Britain, France, Denmark and Norway for 15 days as part of curbs following the discovery of the highly transmissible Omicron variant of COVID-19 in the Middle East"s worst-hit country. State television said on Sunday a similar ban imposed in late November on travellers from South Africa and seven neighbouring countries was also extended for 15 days. Health authorities also indefinitely halted land travel to neighbouring Turkey, a popular tourist destination, the broadcaster said. Iran, the pandemic"s epicentre in the Middle East, has reported just 14 confirmed Omicron cases so far but media reports said detection kits were not widely available and officials have warned of a possible rapid spread within weeks. The country has suffered 131,400 deaths in five waves of COVID-19 infections since February 2020. Nearly 51.3 million of Iran"s population of about 85 million have received two doses of coronavirus vaccine.