Republican Donald Trump on Saturday lashed out at two Muslim American parents who lost their son while he served in the United States (U.S.) military in Iraq and who appeared at the Democratic National Convention last week. This stirred outrage among critics who said the episode proves that Trump lacks the compassion and temperament to be president, according to Washington Post.

Asked to comment on the convention speech of Khizr Khan, a Pakistani immigrant whose son, Army Capt. Humayun Khan, died in Iraq in 2004, Trump described Khan as “very emotional” and said he “probably looked like a nice guy to me” – then accused him of being controlled by the Clinton campaign.

“Who wrote that? Did Hillary’s scriptwriters write it?” he asked in an interview with ABC.

Trump also questioned why Khan’s wife, Ghazala, did not speak on stage, despite the fact that she sat for an interview with MSNBC the following day.

“His wife, if you look at his wife, she was standing there. She had nothing to say. She probably, maybe she wasn’t allowed to have anything to say,” he said. “You tell me, but plenty of people have written that. She was extremely quiet and it looked like she had nothing to say.”

The Khans appeared in Philadelphia on Thursday, the same night that Trump’s Democratic opponent, Hillary Clinton, formally accepted her party’s nomination.

Khizr Khan’s moving remarks quickly reverberated beyond the arena, and their effects have since spilled out onto the campaign trail.

In an interview the following day with MSNBC, Ghazala Khan said she did not speak because she is still devastated by her son’s death and grows emotional when she sees his picture.

Although only the latest instance in which Trump has attacked a convention speaker, the Republican nominee’s remarks drew strong rebukes on Saturday – but only silence from several senior GOP leaders, including House Speaker Paul D. Ryan, Senate Majority Leader Mitch McConnell and the vice-presidential nominee, Indiana Gov. Mike Pence.