(Adds details) BERLIN, July 11 (Reuters) - A young Tunisian suffered life threatening injuries after setting himself on fire outside the Libyan embassy in Berlin on Friday, German police said, adding the man was k**wn to embassy staff and his motivations did **t appear to be political. "A man came to the front of the Libyan embassy with a bottle of lamp oil. The security guards knew this man already, and there have been previous disagreements over his demands for money from the embassy," a police spokesman said.