President Donald Trump on Wednesday said Facebook Inc. was biased against him during the election, marking the second time he has sought to rebut the notion that possible manipulation of the social network could have played a role in his election win.

The heated rhetoric comes as public scrutiny of the role of technology companies played in the election is set to heat up. On Wednesday, the Senate Intelligence Committee invited Facebook Inc., Alphabet Inc.’s Google and Twitter Inc. to testify on Nov. 1 about Russian interference on their platforms, according to people familiar with the matter.

The House Intelligence Committee said it would also hold a hearing with tech companies in October, but it has not yet determined a witness list or a date for the event. Both panels are probing Russian activity during the 2016 election.

Rep. Adam Schiff (D, Calif.), the top Democrat on the House Intelligence Committee, said in the hearings he believed the public would get a look at the actual ads bought by Russia.

“I’d like the public to be able to see the ads so cynically used to try to divide Americans against other Americans,” Mr. Schiff said in an interview.