Thomson ReutersFebruary 1, 2013 08:16
* 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.