An alleged suicide bomb has hit the entrance of the US embassy in the Turkish capital Ankara, killing two security personnel and injuring several others, according to reports.

The explosion took place near the visa building of the embassy. The blast happened while negotiations between the government and the Kurdish Workers Party (PKK) were ongoing.

A local journalist told Sky News: "There was a huge bang which really shook everywhere."

Police stepped up security and cordoned off the area outside the US embassy in Ankara on fears of possible second explosion

Turkish TV footage showed smoke rising, with damage to the side entrance of the US embassy.