Election authority says Maduro, who faced a stiff test from a unified opposition, secured 51 percent of the vote.

Incumbent Nicolas Maduro has been declared the winner of Sunday’s presidential election, but the opposition said they were preparing to dispute the results.

Elvis Amoroso, president of the CNE electoral authority, said Maduro secured a third six-year term with 51.2 percent of the vote. Opposition candidate Edmundo Gonzalez Urrutia, who had been leading in opinion polls, got 44.2 percent, he said.

The electoral authority, which is controlled by Maduro loyalists, did not immediately release the tallies from each of the 30,000 polling stations nationwide.

Opposition representatives said earlier that tallies they collected from campaign representatives at the centres had shown Gonzalez trouncing Maduro.

In comments shortly after the announcement, Maduro said his re-election was a triumph of peace and stability and reiterated his campaign trail claims that the voting system was transparent.

Maduro, 61, first won power in 2013 after his mentor, socialist Hugo Chavez, died from cancer. He has been accused of locking up critics and harassing the opposition and has failed to end a years-long economic crisis that has prompted more than seven million of Venezuela’s 30 million citizens to emigrate.

The opposition campaigned on a promise to end the economic crisis and exit polls suggested they stood a strong chance of beating Maduro.

Gonzalez replaced popular opposition leader Maria Corina Machado on the ticket after authorities loyal to Maduro excluded her from the race.

Machado, who campaigned far and wide for her proxy, had urged voters late on Sunday to keep “vigil” at their polling stations in the “decisive hours” of counting amid widespread fears of fraud.

She said Gonzalez had won 70 percent of the vote.

“We want the whole world to know that we won in every sector and every state in the country. We know what happened today. We’ve been making sure all the information was collected and reported. This shows the results. It is irrefutable,” Corina Machado told a rally.

Analysts also expressed scepticism at the outcome.

“Everything we have seen so far indicates the results of the government are just produced,” Phil Gunson, International Crisis Group’s senior analyst for Venezuela, told Al Jazeera. He claimed the tallies announced by the government-controlled electoral authority did not correspond to the votes cast.

“The result that the opposition claims is the correct one … corresponds very closely to what opinion polls have been saying for the last several months,” Gunson said. “All the partial results we have see so far indicate the opposition got something like three-fifths of the vote.”

Sunday’s election was the product of a deal last year between the government and opposition.

The agreement led the United States to temporarily ease sanctions imposed after Maduro’s 2018 re-election, which was rejected as a sham by dozens of Western and Latin American countries.

But the sanctions were reinstated after Maduro reneged on agreed conditions.

US Secretary of State Antony Blinken, who is currently visiting Japan, said Washington wanted the votes to be counted “fairly and transparently” and expressed concern at the declaration of Maduro’s victory.

“We have serious concerns that the result announced does not reflect the will or the votes of the Venezuelan people,” Blinken said.