President Hugo Chavez returned triumphantly to office two days after he was ousted and arrested by Venezuela's military, raising his fist in the air as he greeted supporters and reclaimed the presidential palace Sunday.

"I'm still stupefied. I'm still assimilating," Chavez said in a live TV address to the nation after flying by helicopter to the palace in Caracas from captivity on a Venezuelan island in the Caribbean, the last of five places where he was held.

Chavez appealed for calm as thousands of Venezuelans thronged the streets outside the gates, singing the national anthem and setting off firecrackers to celebrate his return.

"I do not come with hate or rancor in my heart, but we must make decisions and adjust things," said Chavez, who appeared in good shape, even though he had barely slept since his arrest late Thursday.

In a first step toward conciliation, Chavez announced that a board of directors opposed by executives at state-owned oil monopoly Petroleos de Venezuela has resigned.

What began as an internal power struggle at PDVSA snowballed into popular rebellion by the opposition, triggering a national general strike, a massive demonstration that ended in bloodshed and Chavez's brief ouster.

The Bush administration, which showed no remorse when the Venezuelan military ousted the country's elected president last week, advised Hugo Chavez on Sunday to make good use of a second chance to govern.

"We do hope that Chavez recognizes that the whole world is watching and that he takes advantage of this opportunity to right his own ship, which has been moving, frankly, in the wrong direction for quite a long time," said Condoleezza Rice, President Bush's national security adviser.

She said Chavez "needs to respect constitutional processes" during this tumultuous period in Venezuela, the No. 3 supplier of oil to the United States and the world's fourth biggest exporter.

In a dizzying sequence of events, Chavez was ousted by his military high command, which claimed he had resigned under pressure after gunmen opened fire on opposition protesters. At least 16 people were killed.

Interim President Pedro Carmona was sworn in Friday, only to resign a day later amid widespread street protests and rebellions by several military officers who refused to go along with the plan. Chavez's vice president said Saturday that Carmona and his supporters would be tried.

At least 25 people were killed and hundreds wounded in the upheaval that followed Chavez's ouster. He accused police of using brutal force against demonstrators who called for his reinstatement. Police had reportedly opened fire on some demonstrators in Caracas' slums.

Never before in modern times has an elected president been overthrown by military commanders, his successor inaugurated, and then the ousted leader returned to power on the wings of a popular uprising.

Chavez -- who himself led an unsuccessful coup attempt in 1992 when he commanded a paratrooper unit -- said he was not mistreated in custody, and appealed for calm.

Carmona had angered many by immediately trying to sweep away all vestiges of Chavez's rule by dissolving Congress and canceling the Constitution that was approved under his administration.

Before Carmona resigned, Chavez's vice president claimed the presidency during his boss' absence, denying Chavez had resigned. Vice President Diosdado Cabello handed power back over to Chavez after he was freed, and Chavez confirmed he never resigned.

Cabello said Carmona, supporters who were to have been appointed to his government and military officers involved in Chavez's ouster would be tried for conspiracy of military rebellion. He said the designated Cabinet members and more than 100 military personnel were under arrest.

"They must take responsibility. They will be put on trial with all their rights, but they will be put on trial," Cabello said.

Thousands of demonstrators supporting Chavez -- or opposed to the way he was ousted -- took to the streets Saturday and took over state TV to demand his return.

Several military commanders refused to accept Carmona's appointment and the commander of an air base in the central city of Maracay rebelled. For several tense hours it appeared factions in the divided armed forces would fight each other, but the split did not escalate into violence.

After Carmona resigned, Chavez administration officials -- many of whom had evaded police raids under his brief reign -- and loyalist military officers gathered in the marble-floored courtyard of the presidential palace and hugged each other with relief and joy.

"In these past two days they have persecuted us," said Rafael Ramirez, president of the state-run gas consortium and a Chavez ally.

Unshaven and with red-rimmed eyes, Ramirez said he had hidden in friends' homes after Chavez's arrest. Asked about the turnaround, Ramirez said: "It's marvelous, because the Venezuelan people responded to this illegal coup attempt."

Only hours before the interim president resigned, his designated foreign minister, Jose Rodriguez Iturbe, had met with the ambassadors of the United States and Spain.

In sharp contrast to several Latin American countries that denounced Friday's irregular transition of power, the United States had said Chavez was responsible for his own ouster.

The United States is Venezuela's biggest trading partner, but despite the tight trade relations, the leftist Chavez has irritated Washington by cozying up to Cuba as well as Iraq, Iran and Libya. Chavez was elected in 1998 on an anti-poverty platform, and his term ends in 2006.

Carmona was named president by the military high command Friday, hours after generals arrested Chavez for allegedly ordering gunmen to fire on a massive opposition protest on Thursday. At least 16 died and hundreds were wounded in the melee.

Dozens more died in rioting and looting on Saturday. Caracas Mayor Alfredo Pena said at least nine people were killed and 40 wounded Saturday, but an Associated Press reporter saw dozens of bodies at city hospitals.

Thursday's march capped a general strike called to support oil executives who were protesting Chavez's appointments to the board of directors at Petroleos de Venezuela. A work slowdown at the company severely cut production and exports in Venezuela.

Jesse Chacon, president of Venezuela's telecommunications agency, said TV stations' conduct last week will be investigated. Chacon condemned stations that failed to cover protests against Chavez's ouster and said they falsely depicted a calm Venezuela to help the new regime.

The Organization of American States was sending a delegation to Venezuela to assess the political situation.