VILLAVICENCIO, COLOMBIA (CNN) - A mission to free three hostages held by leftist rebels in Colombia stalled Monday, with the rebels and Colombian authorities trading blame for the delay.

On Monday night, President Hugo Chavez of Venezuela, who organized the mission, said he remained hopeful that the operation would succeed despite major obstacles that surfaced earlier in the day.

The leftist Revolutionary Armed Forces of Colombia, known as the FARC for its Spanish acronym, had planned to release three hostages as part of a deal Chavez brokered. Yet they reversed course Monday and said that Colombian military operations in the area made a release impractical.

VILLAVICENCIO, Colombia (CNN) - A dramatic development raised hopes Monday that a three-year-old boy who was born in captivity in the Colombian jungle may be free.

The boy, known as Emmanuel, was in line for freedom with his mother and another woman who were kidnapped six years ago by a rebel force that the U.S. and Colombia view as a terrorist organization.

 Yet "Operation Emmanuel" appeared to collapse Monday, with the Colombian government and rebels trading blame for the failure of rebels to free the hostages.

As the mission's fate remained clouded in uncertainty, President Alvaro Uribe of Colombia stunned a throng of reporters Monday by saying that Emmanuel may not be in rebel hands after all and that the boy may live in a foster home in the Colombian capital of Bogota.

DES MOINES, Iowa (CNN) - The rivalry between Republican presidential contenders Mike Huckabee and Mitt Romney took another turn Monday as Huckabee announced he would kill an Iowa television ad attacking Romney - then played it for a room full of reporters.

Huckabee said he pulled the commercial because he has decided not to hit back against attacks by the former Massachusetts governor. But he said he made sure the ad got seen - despite multiple glitches during his Monday news conference - "because we wanted to validate that in fact, there was an ad."

Polls show Huckabee and Romney running neck-and-neck race far ahead of the other GOP candidates ahead of Thursday's Iowa caucuses, the first contest of the 2008 presidential race.

Romney responded to Huckabee's move by calling it "kind of confusing." And he defended his own campaign, saying his criticism of the former Arkansas governor was based on issues, not a personal attack.

WASHINGTON (CNN) - The State Department denies it ignored security dangers surrounding former Pakistan Prime Minister Benazir Bhutto when she returned to Pakistan.

State Department spokesman Tom Casey told reporters in his office Monday that the United States had concerns about Bhutto's security before and after she returned to Pakistan. And he disputed claims made Monday in the Washington Post and other newspapers by columnist Robert Novak that security issues had been ignored.

In his column, Novak wrote, "The assassination of Benazir Bhutto followed two months of urgent pleas to the State Department by her representatives for better protection. The U.S. reaction was that she was worried over nothing, expressing assurance that Pakistani President Pervez Musharraf would not let anything happen to her."

–From CNN State Department Producer Charley Keyes

WASHINGTON (CNN) - The Bush administration was hoping to spend the early hours of 2008 poring over a new document from the North Koreans: a full list of its nuclear secrets. No such luck.

The North Koreans let the New Year's Eve deadline come and go without revealing anything.

The United States now is hoping the delay will only be temporary and that the official declaration will be sent along in the coming days. The U.S. goal is to press ahead with negotiations and achieve full denuclearization of the Korean peninsula by the end of the new year.

–From CNN State Department Producer Charley Keyes

BOGOTA, Colombia (CNN) - A 3-year-old child thought to be held hostage since his birth in the jungles of Colombia may actually be in the custody of a child-welfare agency in Bogota, Colombian officials said Monday.

The stunning news came during a press conference given by President Alvaro Uribe of Colombia after a plan to free hostages appeared to have run into serious trouble. The child showed signs of torture and mistreatment, Uribe said.

The mission to free the hostages was dubbed Operation Emmanuel for the child, thought to be the son of kidnap victim Clara Rojas, a Colombian political consultant who was kidnapped six years ago by leftist rebels with the Revolutionary Armed Forces of Colombia, or FARC, the Spanish acronym by which the group is known.

(CNN) - The driver of a pick-up truck involved in a wrong-way accident that killed a mother and four children will be charged with five counts of vehicular homicide upon his release from hospital, Toledo (Ohio) Police Chief Michael Navarro told CNN Monday.

Michael Gagnon, 24, was allegedly drunk when he sped north on the southbound side of Interstate 280 and hit a minivan carrying eight people - a mother, father, and their six children or stepchildren - said Toledo Fire Department Assistant Chief Luis Santiago.

Toledo police Capt. Ron Spann said police received notification of a wrong-way driver on I-280 about 10:52 p.m.; Gagnon crashed into the Griffin family's Chevy Astro Van three minutes later. Police arrived on the scene at 10:57 p.m., he said.

– From CNN's Sarah B. Boxer in New York

BAGHDAD (CNN) - While 2007 has been the deadliest year for U.S. troops in Iraq, December marks the second-lowest monthly death toll of the war.

As of evening Dec. 31 in Baghdad, the U.S. government has reported 899 U.S. troops killed in Iraq in 2007. Last year the toll was 822. The reported death toll for December stands at 21. The only lower monthly toll was 20 in February 2004.

An official with Iraq's Interior Ministry said Friday 2007 brought the highest-ever civilian death toll in the war, with 16,232 civilians killed. Last year, the ministry said 12,371 civilians were killed. The official said 481 Iraqi civilians were killed in December - the lowest reported monthly toll for the year.

But civilian casualties in Iraq are impossible to confirm, and questions have been raised about how the Iraqi government decides which deaths to blame on the war. The United Nations said more than 34,000 Iraqi civilians were killed in violence in 2006.

(CNN) - Colombian military operations are "prohibiting" the release of three hostages whom Colombian leftist rebels promised to free, the group said in a statement that Venezuelan President Hugo Chavez read on Venezuelan television.

Colombian President Alvaro Uribe denied the group's assertion, and said there are no combat operations in the area. The Colombian government had given all necessary assurances for the successful completion of the humanitarian mission, Uribe said during a televised news conference.

Earlier Monday, Colombia's peace negotiator accused the group of lying and delaying the hostages' release, saying FARC had not provided the "pertinent information," or coordinates regarding where the freed hostages could be picked up.

NAIROBI, Kenya (CNN) - One of the most stable nations in east Africa descended further into chaos Monday after a disputed election triggered violence that has killed at least 124 people.

The deaths in Kenya came as opposition supporters fought with police firing tear gas and live ammunition.

They were protesting the government's announcement Sunday that voters had re-elected President Mwai Kibaki with 51.3 percent of the vote, compared with 48.7 percent for Raila Odinga, the opposition leader. International election monitors have alleged voting irregularities.