In an interview on Monday, Mr. Abdullah said that his 20,000 observers had reported results to him, but that he was going to wait until the election commission released its official tallies before speaking about his own. “We have to respect the rule of law here,” he said.

But people involved in his campaign released figures they said were based on analysis of 2.25 million votes (about one-third of the total cast), showing Mr. Abdullah with 50 percent; by their reckoning, Mr. Ghani was running second with 38 percent and Mr. Rassoul third with 10 percent.

Whatever the credibility of these rival counts, it seemed likely that the contest was coming down to Mr. Ghani and Mr. Abdullah. Mr. Ghani claimed as much in an interview Sunday: “The pattern has become clear, the losers are clear. It has become a two-way race, whatever else one says.”

For his part, Mr. Rassoul has been silent about the results. One of his supporters, though, Gen. Helaluddin Helal, a former deputy interior minister who works on Mr. Rassoul’s campaign, said his two opponents’ tallies were suspect, and in some places showed more votes cast than there were residents to cast them. “Those votes are not real votes,” he said. “Rassoul is not giving up.”

Still, a former Afghan official who is close to Mr. Rassoul said his campaign had concluded that it would most likely place third behind Mr. Ghani and Mr. Abdullah.