Still no proof of collusion with Russians, says Donald Trump

Donald Trump has appeared to confirm he is under investigation for obstruction of justice, claiming he is being probed for firing FBI director James Comey by the man who told him to do it.

It was not clear whether the president was basing his tweet on direct knowledge, or on reports this week that special counsel Robert Mueller is examining whether he obstructed justice by firing Mr Comey last month amid the Russia investigation.