Venezuelan President Hugo Chavez was re-elected Sunday to a new six-year term, overcoming an energetic challenge by a candidate backed by an opposition coalition, according to nearly complete results announced by election officials.

Chavez, who has been president since 1999, defeated Henrique Capriles Radonski, whose campaign criticized the Chavez administration for inefficiencies, infrastructure shortcomings and corruption.

Chavez highlighted his accomplishments in housing, education and health initiatives and acknowledged he need to do more on crime and government bureaucracy.

With 90% of the ballots counted Sunday night, Chavez has 54.42% of the vote compared with 44.97% for Capriles, according to Tibisay Lucena, president of the National Electoral Council.

Chavez had secured 7.4 million votes and Capriles 6.1 million votes, election officials said.

The country saw one of its high participation rates in decades, with almost 81% of voters going to the polls, Lucena said.

In fact, some polls were kept open two hours after their scheduled closing because of lines of voters waited for ballots.

As throughout the day, the army was still deployed Sunday evening and was standing by throughout the country to ensure a peaceful and secure vote, said Maj. Gen. Wilmer Barrientos, commander of strategic operations command.

Earlier in the evening, Chavez thanked his campaign staff in a phone call aired on state-run television at mid-evening and asked people to remain calm until the election results were completed. Chavez said people were still voting in some places.

"Let us wait for the results patiently, calmly and prepare ourselves to accept the results whatever they may be," he said.

"This will be a triumph for democracy," he added. He asked that there be no violence.

Long lines began forming in the early morning hours at polling stations from remote regions of the Amazon to the bustling capital of Caracas.

One election official, Rosalin Montiel, told state-run television that polling stations in the municipality of San Francisco in the state of Zulia would remain open past the schedule closing time -- "until the last elector casts his vote."

Nearly 140,000 troops were deployed throughout the country to guard polls and keep the peace, state-run VTV reported.

By mid-afternoon, Barrientos reported 15 electoral offenses throughout the entire country, the Venezuelan military said on its Twitter account. No further details were immediately available.

After casting his ballot, Chavez called on Venezuelans to vote and remain calm.

"Have no doubt that we will respect the results, whatever they are. ... We have to recognize the results," he told reporters.

After casting his vote, Capriles said governors nationwide had reported "massive participation, demonstrating one more time that Venezuelans want to resolve our differences through democratic means."

He told reporters that "whatever the people say today, for me, is sacred," and said he would push for national unity after the results are released.

"There will be a winner. There will a president-elect. But there will not be a defeated people," he said. "Tomorrow, we are only one country, only one Venezuela. Tomorrow in the country there are many problems that we have to resolve. Problems do not wait."