Actors accused of 'high treason' after meeting with US lawmakers The actors are known for their roles in "Syriana" and "Vikings."

CAIRO -- Two Egyptian actors were accused of "high treason" for holding a series of meetings with U.S. lawmakers this week about alleged violations by their current government.

On Monday, Amr Waked and Khaled Abo El-Naga, along with human rights advocates, conducted a series of meetings in Washington, D.C. with members of the U.S. Congress to lobby against human rights violations in Egypt and controversial proposed constitutional amendments.

Among the proposed amendments Waked and El-Naga — who is internationally known by Kal Naga — are protesting the extension of the presidential term from four to six years and abolishing the two-term limit for a president to serve.

The meeting with the U.S. lawmakers came ahead of a congressional briefing on Monday titled "Egypt: Constitutionalizing Authoritarianism."

Shortly after the actors had their meeting, the Egyptian Actor's Syndicate — an actor's union in Egypt — issued a statement revoking their membership and accusing them of "high treason to the nation and to the Egyptian people."

They were further accused of lobbying in favor of "the agendas of those plotting against Egypt’s safety and stability."

"There is no shame in meeting with the members of the American Congress to express opinion and reinforcing the interests of the Egyptian people in first world countries, like all lobbyists do," Waked, who is known internationally for his role in the movie "Syriana," wrote on Twitter.

Both Waked and Naga, two prominent names in their country, are known for their political activism since the 2011 uprising that led to the ouster of former president Hosni Mubarak, in a wave of anti-government protests that swept the region and was later known as the Arab Spring.

"I wish the syndicate had at least called or checked the facts before rushing with such false accusations and making a decision that only undermines its credibility," Naga, who plays Zyiadat Allah in the historical television drama "Vikings," tweeted.

A lawsuit was filed on Wednesday by Ayman Mahfouz, an Egyptian lawyer, accusing Naga, currently based in California, of using social media to promote ideas that incite terrorist activity, according to Egyptian newspaper Al-Youm Al-Sabaa.

Earlier this month, Waked told ABC News that he feared returning to Egypt from Europe, where he now resides, after he said he was sentenced to eight years in military prison for holding critical views.

Also this week, one of Egypt's best-selling artists, Sherine, was banned by the musician syndicates from singing in Egypt and and face investigations over remarks she made during a concert in Bahrain where she suggested that Egypt doesn’t respect freedom of speech.