WASHINGTON, Feb 1 (Reuters) - The U.S. State Department said it is working with Turkish officials to investigate a deadly explosion outside the U.S. embassy in Ankara on Friday. "We are working closely with the Turkish national police to make a full assessment of the damage and the casualties, and to begin an investigation," department spokesperson Victoria Nuland said in a statement.

* Bomber, Turkish guard killed in blast * Interior Minister blames leftist group * White House says motivation unclear * U.S., British missions call for vigilance (Adds White House, bomber's reported identity, details) By Jonathon Burch ANKARA, Feb 1 (Reuters) - A far-leftist suicide bomber killed a Turkish security guard at the U.S. embassy in Ankara on Friday, officials said, blowing open an entrance and sending debris flying through the air.

One person was killed and several others were wounded on Friday in an explosion outside the US embassy in Ankara that damaged nearby buildings, the NTV news channel reported. Police cordoned off the street in the Cankaya neighbourhood where many other state institutions and embassies are also located. It was not immediately clear what caused the blast. fo-ck/yad