Special counsel Robert Mueller is not yet done investigating whether the Trump campaign colluded with Russia during the 2016 election after indicting 13 Russian nationals and three Russian entities for seeking to interfere in the 2016 election, according to a report Friday.

The indictments cover just a portion of the investigation, which is expected to continue on for months, a person familiar with the probe told Bloomberg. The probe is also seeking to determine if Trump obstructed justice, the person said. Mueller has not publicly confirmed that his team has ever looked into possible efforts obstruct justice.

Mueller’s office on Friday revealed that the 13 Russian nationals were indicted on charges of conspiracy to defraud the U.S. Additionally, three defendants were charged with conspiracy to commit wire fraud, and five were charged with aggravated identity theft.

Deputy Attorney General Rod Rosenstein, who is overseeing Mueller’s probe, announced Friday afternoon that the meddling started in May 2014 and that the Russian groups created posts, ads, and organized events on social media platforms by using names of Americans and other entities.

The ads primarily were primarily opposed to Democratic nominee Hillary Clinton, but at times were against President Trump. The indictment also said that the indictment does not suggest members of Trump's campaign were wittingly involved with the scheme.

Mueller is investigating if collusion between the Trump campaign and the Kremlin occurred during the 2016 election.

Trump has historically called Mueller’s probe a “witch hunt” and, in light of the Russian indictments, has continued to reiterate that “no collusion” ever happened.

"Russia started their anti-US campaign in 2014, long before I announced that I would run for President," Trump tweeted on Friday. "The results of the election were not impacted. The Trump campaign did nothing wrong — no collusion!"