Demonstrators march as they take part in an anti-Trump "March for Truth" rally on June 3, 2017 in New York City.
Demonstrators march as they take part in an anti-Trump "March for Truth" rally on June 3, 2017 in New York City.

Protests were underway Saturday in more than 135 cities in the U.S. and around the world to demand an impartial investigation into any potential collusion between President Donald Trump's campaign and Russia to influence last year's election in Trump's favor.

The "March for Truth" protests were organized by a national coalition of 17 activist groups, including the Women's March and the Progressive Democrats of America.

The coalition is demanding that an independent commission be established to oversee an impartial probe and that ongoing congressional investigations be "properly resourced and free of partisan interests."

Both houses of Congress are investigating potential Trump campaign links to Russia and Moscow's meddling in the election. In addition, the Justice Department appointed former FBI Director Robert Mueller as a special counsel to probe whether Trump campaign aides illegally colluded with Russia.

The investigations were launched after U.S. intelligence agencies concluded Russia had hacked the computer servers of the Democratic National Committee last year to try to harm the campaign of Democratic Party candidate Hillary Clinton, whom political analysts say Russian President Vladimir Putin despised.

So far, though, no evidence has been released showing any collusion between the Trump campaign and Russia during the election.

Rep. Jamie Raskin, D-Md., speaks to demonstrators
Rep. Jamie Raskin, D-Md., speaks to demonstrators gathered near the Washington Monument during the "March for Truth," June 3, 2017, in Washington, D.C.

Democratic Representative Jamie Raskin of Maryland, who spoke at an anti-Trump rally in Washington, told VOA he would like to see an additional investigation of any potential collusion, on top of the three current investigations.

"No Democratic politicians, no Republican politicians. An independent, nonpartisan commission outside of Congress to investigate what happened and deliver us a report," Raskin said.

Trump has rejected allegations of collusion and dismissed the U.S. intelligence community's assessment that Putin ordered an influence campaign aimed at disrupting the November election. Putin has repeated there is no evidence of Kremlin involvement in the election.

WATCH:  Protesters chant demanding justice

"March for Truth" organizers were also demanding that Trump release his personal tax returns. Trump has repeatedly refused to disclose them, raising the ire of critics who contend his refusal leaves citizens without information regarding his potential conflicts of interest or how his proposed tax policy overhaul may help enrich himself. There is no law compelling a U.S. president to release tax returns.

The "March for Truth" protests were the latest in a number of weekend anti-Trump protests since his election, including the Women's March in January and the March for Science in April.

While anti-Trump protesters in the U.S. capital held their event near the Washington Monument on Saturday, a group of about 250 Trump supporters gathered a few blocks away, in front of the White House, for a "Pittsburgh Not Paris" rally to celebrate Trump's decision to pull out of the Paris climate change agreement.

Trump announced Thursday his decision to pull out of the global climate agreement, joining Syria and Nicaragua as the only countries that are not part of it.

Demonstrators take part in an anti-Trump "March fo
Demonstrators take part in an anti-Trump "March for Truth" rally at Foley Square on June 3, 2017 in New York City.

Steve Buckingham, the executive director of the Fairfax County (Virginia) Republican Committee, co-sponsored the event. He told VOA the "Pittsburgh Not Paris" rally was meant to show Trump that his supporters backed his decision.

Like several others at the rally with whom VOA spoke, Buckingham said he thought other countries weren't contributing enough financial support under the current agreement and that it would hurt the U.S. economy if America honored the deal signed by former President Barack Obama.

"It was weak. There were no enforcement mechanisms, the goals were based on hope and suggestion, and it was just a bad agreement for us to be in. So we're glad that President Trump is keeping his promises and pulling us out of agreements like that," he said.

WATCH: Pro-Trump protesters chant near White House

The name for the pro-Trump rally was a reference to one of the lines in the speech Trump gave when he announced the decision to pull out of the agreement. Trump said the accord did little to help the environment and unfairly punished the U.S. by holding it to tougher standards than other top polluters.

Trump rejected the accord as an attempt by "foreign lobbyists" who want the U.S. "tied up and bound down" so that their countries can have the "economic edge."

"I was elected to represent the citizens of Pittsburgh, not Paris," Trump said.