An electronic voting technology company that tracked voting in Sunday's Venezuelan elections to overhaul the country's constitution says the turnout was "manipulated" by at least 1 million votes.

"We know, without any doubt, that the turnout of the recent election for a National Constituent Assembly was manipulated," said Antonio Mugica, CEO of Smartmatic, at a Wednesday news conference in London. "We estimate the difference between the actual participation and the one announced by authorities was at least 1 million."

Mugica said the discrepancy of 1 million votes was between tallies announced by the government and those counted by his company's systems.

Venezuela Political Crisis FILE - Opposition lawmaker Richard Blanco speaks during a session at the National Assembly in Caracas, Venezuela, Aug. 1, 2017. The president of the opposition-led National Assembly, Julio Borges, told Venezuela that Maduro's foes would continue protesting until they won free elections and a change of government. FILE - Opposition lawmaker Richard Blanco speaks during a session at the National Assembly in Caracas, Venezuela, Aug. 1, 2017. The president of the opposition-led National Assembly, Julio Borges, told Venezuela that Maduro's foes would continue protesting until they won free elections and a change of government.

Tampering

Mugica declined to say whether the tampering changed the outcome of the election, which may be challenged by the opposition-controlled National Assembly. Assembly President Julio Borges said Smartmatic's findings are "complete confirmation" of what the opposition and election analysts had suspected and added that lawmakers will ask the country's top prosecutor to investigate members of the National Election Council for potential crimes.

The council did not immediately comment on the findings.

The government said more than 8 million people cast ballots. The opposition, which boycotted the vote, said the turnout was much lower. Reporters in Caracas said dozens of polling places were almost deserted Sunday.

Even if 8 million people did cast ballots, that would be less than half of all registered voters. Pre-election polls indicated more than 70 percent of all Venezuelans opposed the election of an assembly to rewrite the constitution.

A screen grab from cellphone footage shows opposit FILE - A screen grab from cellphone footage shows opposition leader Antonio Ledezma being taken away from his home forcibly by the intelligence service while still wearing pajamas, in Caracas, July 31, 2017. FILE - A screen grab from cellphone footage shows opposition leader Antonio Ledezma being taken away from his home forcibly by the intelligence service while still wearing pajamas, in Caracas, July 31, 2017.

The opposition contended the vote was rigged to pack the assembly with Maduro supporters who could dissolve the opposition-controlled national assembly, and fire officials who disagree with the government. Maduro's opponents are demanding early presidential elections, which have been scheduled for 2018.

U.S. President Donald Trump, meanwhile, says he is holding Venezuelan President Nicolas Maduro "personally responsible" for the health and safety of two opposition leaders taken from their homes by police early Tuesday morning.

"The United States condemns the actions of the Maduro dictatorship," Trump said in a statement late Tuesday. "Mr. Lopez and Mr. Ledezma are political prisoners being held illegally by the regime ...we reiterate our call for the immediate and unconditional release of all political prisoners."

'All who cherish freedom'

During a visit Wednesday in Montenegro with Prime Minister Dusko Markovic, U.S. Vice President Mike Pence urged "all who cherish freedom to condemn the Maduro regime for its abuse of power and its abuse of its own people. Venezuela deserves democracy and the Venezuelan people deserve freedom."

U.S. Vice President Mike Pence, gestures during th U.S Vice President Mike Pence, gestures during the opening session of the Adriatic Charter Summit in Podgorica, Montenegro, Wednesday, Aug. 2, 2017. U.S Vice President Mike Pence, gestures during the opening session of the Adriatic Charter Summit in Podgorica, Montenegro, Wednesday, Aug. 2, 2017.

Twitter video purportedly shows intelligence agents dragging Leopoldo Lopez and Antonio Ledezma out of their homes early Tuesday morning and shoving them into cars.

The two were under house arrest for previous opposition activities. The Venezuelan Supreme Court says "official intelligence sources" warned that Lopez and Ledezma were planning to flee. The court said they broke the terms of their house arrest by "political campaigning" and "making statements to the media," encouraging protests against the Maduro government.

Lopez' lawyer, Juan Carlos Gutierrez, denied his client violated his house-arrest regulations. He said Lopez was only forbidden from talking about his own case.

Lopez and Ledezma, both former mayors, each had posted videos urging their followers to boycott Sunday's election. Lopez previously spent three years in jail on charges of instigating violence during anti-Maduro street protests in 2014; Ledezma was convicted in 2015 on charges of plotting a coup against Maduro.

The U.S. imposed sanctions against Maduro on Monday for what it called his "illegitimate" election of an assembly to rewrite the constitution. All of Maduro's assets in the United States have been frozen and Americans are forbidden from doing any business with him.

Maduro says he does not care. He raged on Venezuelan television: "They don't intimidate me. The threats and sanctions of the empire don't intimidate me for a moment...Bring on more sanctions, Donald Trump."

Dismissed US charges

Venezuelan Defense Minister Vladimir Padrino dismissed U.S. charges that Maduro is a dictator. He said dictators do not hold elections, invoke the constitution and work for peace to avoid civil war.

Jennifer McCoy, a distinguished professor at Georgia State University and former director of the Carter Center's Americas program, said some legislators who are members of Maduro's United Socialist Party have distanced themselves as a critique of Sunday's election and the government's actions.

FILE - Venezuela's President Nicolas Maduro talks FILE - Venezuela's President Nicolas Maduro talks to the media during a news conference at Miraflores Palace in Caracas, Venezuela, June 22, 2017. FILE - Venezuela's President Nicolas Maduro talks to the media during a news conference at Miraflores Palace in Caracas, Venezuela, June 22, 2017.

?"There have been some other defections from former Chavistas who are also critical of what the government has been doing," McCoy told VOA. "If a group of dissident Chavistas grows, that provides sort of a third or a middle ground. If they united with the opposition, then that isolates the government further along with the international isolation that seems to be growing. With those two tendencies we may see eventually a willingness for real talks to begin."

McCoy also said that so far the Venezuelan military has supported Maduro.

The Maduro government is determined to form the 545-member constituent assembly. Details on what might be included in a new constitution are unclear. Maduro has said it is the only way to pull Venezuela out of its severe economic and social crisis and curtail political violence.

National Guard soldiers detain an anti-government FILE - National Guard soldiers detain an anti-government demonstrator during clashes in Caracas, Venezuela, July 28, 2017. FILE - National Guard soldiers detain an anti-government demonstrator during clashes in Caracas, Venezuela, July 28, 2017.

The drop in global energy prices and political corruption have destroyed Venezuela's oil-rich economy. Gasoline, medicine and such basic staples as cooking oil, flour, and sugar are scarce, and many Venezuelans cross into neighboring Colombia and Brazil to buy food.

Maduro has blamed the country's woes on what he calls U.S. imperialism and its supporters inside Venezuela. He has warned against intervention by the Organization of American States, saying that would surely lead to civil war.

A spokesman for United Nations Secretary-General Antonio Guterres said the U.N. chief is urging Venezuelans, particularly their leaders, to make all possible efforts to de-escalate tensions, saying the "only way forward is a political solution."