My sources in Turkey are reporting that all the countries provincial police forces have been warned of possible attack by Islamic State (IS) in Ankara on May 19th during the festivities surrounding the countries Youth and Sports Day celebrations.
Turkish National Intelligence are warning that ten IS militants have gained access to the country via the porous boarders with Syria near Gaziantep, in the southeast part of the country, and are headed for more the more ‘target rich’ environments of the cities further west. Of particular interest to the IS operatives is Ankara, the capital of Turkey, with Anıtkabir Mausoleum, the U.S. Embassy, and a military compound located in the neighbourhood of Cebeci, being highlighted as possible targets.
Looking at the capability and previous operational tactics used by IS in Turkey, and the extra dynamic of the PKK and their ongoing struggle with the Turkish government, the threat of a terroris attack has been designated as ‘credible.’

My advice would be to remain extra vigilant and avoid locations government locations and places frequented by tourists for at least the next 48-72 hours. The UK Gov Travel Advice page is currently not showing this information but advises that ‘further attacks are likely.’
If you are currently in Ankara I would advise an ‘essential move only’ protocol be implemented immediately.
‘Be vigilant, follow the advice of local security authorities, monitor media reports and keep up to date with this travel advice.’