Venezuelans lined up to vote Sunday in the toughest election President Hugo Chavez has ever faced, with his near 14-year socialist revolution at stake against fresh-faced rival Henrique Capriles.

Voters stood in long lines to cast their ballots after Chavez supporters played military-style bugles before dawn to rally loyalists of the president, who is seeking a new six-year term to cement his oil-funded revolution.

Venezuelans packed the streets of Caracas and other cities Thursday to hear President Hugo Chavez and opposition rival Henrique Capriles make their final pitches ahead of weekend elections.

As a downpour fell on Caracas, Chavez, who is seeking a new six-year term in Sunday's presidential vote, addressed hundreds of thousands of supporters who waved flags, danced and chanted: "Ooh! aah! Chavez won't go!"

After breezing through past elections, Venezuelan President Hugo Chavez entered the last week of campaigning Sunday against a rival who has gained ground in opinion polls.

The leftist leader, in power for almost 14 years, is vying for a fourth term in office that would extend his presidency by another six years, but opposition candidate Henrique Capriles hopes to pull a major upset on October 7.

A Chinese rocket on Saturday successfully launched a Venezuelan earth-observation satellite into orbit, state media said.

The satellite, dubbed "Generalissimo Francisco de Miranda" after the major Venezuelan independence figure, was launched from the northwest Jiuquan base in the Gobi desert using a 'Long March' class rocket, said Xinhua.

Venezuelan firefighters battled Monday to extinguish a devastating fire at the country's main oil refinery as President Hugo Chavez slammed reports that poor maintenance was to blame.

The Venezuelan leader promised an investigation into Saturday's tragedy that left 41 people dead -- a gas leak is the suspected cause -- and three days of national mourning were declared ahead of his trip to the Amuay refinery, in the country's far north.

Venezuela was in mourning Sunday after a massive explosion tore through the country's largest refinery, killing at least 39 people and injuring more than 80 others.

President Hugo Chavez declared three days of national mourning Saturday, saying the tragedy affected "the great Venezuelan family, civilian and military."

President Hugo Chavez announced Thursday that security forces arrested a U.S. citizen and suspect he is a mercenary who could be involved in an alleged plot to destabilize Venezuela if the opposition's candidate loses the upcoming presidential election.

Chavez said the Hispanic man was detained Aug. 4 while crossing into Venezuela from Colombia. The president said the man was carrying a U.S. passport with entrance and exit stamps from countries including Iraq, Afghanistan and Libya as well as a notebook containing geographical coordinates.

The United States on Wednesday named five Colombia and Venezuela-based men as key players in a sprawling trafficking and money laundering network of alleged Hizbullah-linked Lebanese drug lord Ayman Joumaa.

The U.S. Treasury set sanctions on two Lebanese-born men, Abbas Hussein Harb and Ibrahim Chibli, for helping Joumaa launder what it said were millions of dollars of narcotics-related proceeds.

Paraguayan lawmakers impeached President Fernando Lugo on Friday over his handling of a deadly land dispute, prompting an angry din across Latin America and refusals to recognize his successor.

In a 39-to-4 vote, senators found Lugo, a 61-year-old former Catholic priest with a string of outstanding paternity cases, guilty of performing his duties badly during a land dispute last week that left 17 people dead.

Venezuelan President Hugo Chavez and his Iranian counterpart Mahmoud Ahmadinejad pledged Friday to stand together to battle "imperialism," with Chavez criticizing tough sanctions on Tehran.

Upon his arrival in Caracas from Brazil, where he attended the U.N.-sponsored Rio+20 summit on sustainable development, Ahmadinejad said: "We will build our countries, and we will get away from all the pressures of imperialism."