WASHINGTON (Reuters) - The Democratic congressman leading the impeachment inquiry into President Donald Trump said Trump’s attack on former U.S. Ambassador to Ukraine Marie Yovanovitch on Friday was part of a pattern of intimidating witnesses.

“This is a part of a pattern to intimidate witnesses, and it’s also part of a pattern to obstruct the investigation. It was also a part, frankly, of the pattern to obstruct justice,” Adam Schiff, chairman of the House Intelligence Committee, told reporters after Trump launched a Twitter attack on Yovanovitch while she was testifying before the panel.