TBILISI, Georgia -- Georgian Prime Minister Zurab Zhvania was found dead yesterday following an apparent gas leak from a heater, dealing a blow to the young government's efforts to wipe out corruption and resolve two simmering separatist conflicts in the former Soviet republic.

Authorities played down any hint of foul play, but many Georgians were skeptical, given the impoverished country's history of often-violent political intrigue. One lawmaker linked Zhvania's death and a car bombing in a town west of the capital two days earlier, and hinted at Russian involvement.

Georgian President Mikhail Saakashvili was visibly shaken by the death of the 41-year-old Zhvania, who played a key role in the "Rose Revolution" that brought the leader to power little more than a year ago.

Hundreds of Tbilisi residents, many with tears in their eyes, gathered outside the home of Zhvania's mother to watch his wooden coffin carried inside.

Saakashvili said he would take on Zhvania's duties. "I assume control over the executive branch, and I call on members of the Cabinet to return to work and to continue their work as normal," Saakashvili said.

Eduard Shevardnadze, the longtime Georgian leader who was forced from power by popular protests in late 2003 led in part by Zhvania, called the death of his onetime ally "an irreparable loss."

Secretary of State Condoleezza Rice also called Saakashvili yesterday to express condolences.

Several Tbilisi residents said the death was suspicious. Authorities "have removed Zhvania from the political scene and have cleared the way ... for themselves," said Kote Dgebuadze, a 55-year-old engineer.

An autopsy was under way. Initial tests showed Zhvania's blood had nearly double the fatal level of carbon monoxide, a forensics service spokeswoman said. FBI experts also would help conduct forensics tests, either in the United States or in Turkey, according to the prosecutor general's office.

The prime minister was visiting the Tbilisi apartment of his friend, Zurab Usupov, deputy governor of the Kvemo-Kartli region, who also died, Interior Minister Vano Merabishvili said on Rustavi-2 television.

Zhvania arrived at the apartment about midnight Wednesday, and when his security guards heard no signs of life about four hours later, they broke in through a window, Merabishvili said. "It is an accident," he said. "We can say that poisoning by gas took place."

A gas-fired heating stove was in the main room of the apartment. An open backgammon set, along with a loaf of bread and pieces of sausage were on a table in the room.