Zimbabwe's President Emmerson Mnangagwa was sworn in for a second five-year term Monday, a week after securing an absolute majority in a disputed presidential vote.

The 80-year-old Mnangagwa took the reins of power for another term in a colorful ceremony attended by thousands of Zimbabweans and regional leaders including the presidents of South Africa, the Democratic Republic of Congo and Mozambique.

Mnangagwa was reelected after winning more than 2 million votes - 52.6% of the total ballots - to defeat his main challenger, Nelson Chamisa of the Citizens Coalition for Change (CCC) party, who received 44% of the votes, according to the Zimbabwe Electoral Commission.

Chamisa's party rejected the results, alleging electoral fraud, and called for fresh elections. The hotly contested poll was also criticized by observers, who said the election process fell short of many regional and international standards.

In a preliminary report, the European Union Election Observation Mission (EU EOM) said "fundamental freedoms were increasingly curtailed" during the elections, and that "acts of violence and intimidation" resulting in a "climate of fear" were also witnessed during the polls.

A total of 41 election monitors were arrested by Zimbabwe's police, ahead of the final tally of the votes, for allegedly coordinating the release of results.

The arrests had followed the release of a report by the Zimbabwe NGO Forum that documented irregularities on polling day, according to Amnesty International.

The opposition CCC party told CNN on Monday it will not challenge Mnangagwa's victory at the courts, because it is unsure of getting justice through the country's legal system.

"Our courts are compromised ... it's pointless to seek remedy in a lopsided court," said CCC spokesperson Promise Mkwananzi.

"We are challenging the results politically and diplomatically," Mkwananzi added. "We are calling for a fresh, free and fair election ... We'll be applying pressure at the diplomatic level and also locally in the country, in which we are saying the citizens must insist that their votes must be respected, and their votes must count."

The August 23 vote was the second election in Zimbabwe since authoritarian leader Robert Mugabe was deposed by the military in 2017.

Mnangagwa, nicknamed "The Crocodile," succeeded Mugabe after helping to orchestrate the coup that ousted him.