Ukraine armed forces on full alert

Anti-Yanukovych protesters sing Ukraine's national anthem in Kiev's Independence Square, the epicentre of the country's current unrest (AP)

Ukraine's acting president has ordered the country's armed forces on full readiness because of the threat of "potential aggression".

Speaking live on Ukrainian TV, Oleksandr Turchynov said he had also ordered security to be stepped up at nuclear power plants, airports and other strategic infrastructure.