CARACAS: The announcement of President Hugo Chavez's return to Venezuela after a 10-week silence in Cuba is raising questions about his cancer treatments, his delicate health, and the political purposes that motivated his homecoming.

Three messages appeared on Chavez's Twitter account early Monday saying he was back, and the government announced that he had arrived at 2:30 a.m. and was taken to Caracas' military hospital to continue with his treatments. The government released no images of the president, though, and while his supporters threw street celebrations to welcome him, some also said they wanted to see him to get a better idea of how he is doing.

The government has said Chavez is undergoing "complex and tough" treatments for his illness but hasn't specified what sort of treatment. The government has said he is breathing through a tube inserted into his windpipe and therefore has difficulty talking, but officials haven't given a detailed medical report despite demands by the opposition.

Even as Vice President Nicolas Maduro has increasingly stood in for Chavez since the president's Dec. 11 surgery, he and other leading officials have insisted that Chavez remains in charge and has been signing off on government decisions.

Chavez's announced return to Caracas came less than three days after the government released the first photos of the president in more than two months, showing him in a bed looking bloated and smiling alongside his daughters. The lack of any images of Chavez on Monday underlined the many unanswered questions about where he stands in his prolonged struggle with an undisclosed type of pelvic cancer.

Information Minister Ernesto Villegas broke into song on television early Monday, exclaiming: "He's back, he's back!"

"Bravo," Villegas said, before state television employees joined him in the studio clapping and celebrating.

A giant inflated Chavez doll was placed beside a corner of the National Assembly building.

Villegas reiterated in an interview with Venezuelan radio station Union Radio that Chavez is going through a "difficult, hard and complex" recovery process, and that his return doesn't change the "difficult circumstances he has been in."

The vice president later presided over a televised Cabinet meeting at the presidential palace, though he didn't offer additional details about Chavez. "He will live and he will triumph," Maduro said at the end of the meeting, while on television an image of Chavez's face was superimposed on the oval-shaped table.

Hundreds of Chavez supporters celebrated his return in downtown Caracas, chanting his name and holding photos of the president in Bolivar Plaza. Supporters also gathered outside the hospital, wearing the red T-shirts of Chavez's socialist movement and chanting: "He's back!"

"I want to see my president," said Alicia Morroy, a seamstress who stood outside the hospital on the verge of tears. "I've missed him a lot because Chavez is the spirit of the poor."

Six hospital employees who were asked about the president said they hadn't seen him. Yusmeli Teran, a waitress who serves food to patients, told The Associated Press that the area where Chavez was being treated on the 9th floor is a restricted area guarded by police and soldiers. "No one has seen him at all," she said.

Chavez's precise condition and the sort of cancer treatments he is undergoing remain a mystery, and speculation has grown recently that he may not be able to stay on as president.

Dr. Carlos Castro, scientific director of the Colombian League Against Cancer in Bogota, Colombia, said that given the government's accounts that Chavez is undergoing "complex" treatment, he thinks he likely will have to step down.

"Unfortunately, the cancer he has isn't going to go away, and he's returning to continue his battle. But I think he's conscious that he isn't going to win his fight against cancer, as much as he'd like to win it," Castro told the AP in a telephone interview.

The Venezuelan Constitution says that if a president dies or steps down, a new vote must be called and held within 30 days. Chavez raised that possibility before he left for Cuba in December by saying that if necessary, Maduro should run in a new election to replace him.

Chavez's return could be used to give a boost to his would-be successor and gain time to "consolidate his alternative leader" ahead of a possible new presidential vote this year, said Luis Vicente Leon, a Venezuelan pollster and political analyst.

Leon said that even if Chavez isn't seen in public, his presence will allow the government to keep up his emotional connection to his followers and rally support.

Even the state newspaper Correo del Orinoco referred to the possibility of a new election in its Monday edition. The top headline, published before Chavez's announced return, said a poll found Maduro would win a possible election.

Maduro and other Cabinet ministers held hands and prayed in a televised gathering on Monday night in which a priest and a minister offered words of thanks for Chavez's return.

Venezuela's opposition responded to the news by saying that it's natural for the president to be back in his own country and that creating a "spectacle" with his return serves no useful purpose.

"The government should tell the truth and dedicate itself to working to confront Venezuelans' serious problems," the opposition coalition said in a statement, citing problems such as violent crime, soaring inflation and worsening shortages of some foods.

The 58-year-old Chavez was re-elected to a new six-year term in October, and his inauguration, originally scheduled for Jan. 10, was indefinitely postponed by lawmakers in a decision that the Supreme Court upheld despite complaints by the opposition.

Some speculated that with Chavez back, he could finally be sworn in. But government officials haven't yet addressed that possibility.