MOSCOW » Where’s Putin?

The question obsessed Moscow and much of Russia on Friday, as speculation mounted as to why President Vladimir V. Putin had not been seen in public for more than a week.

He abruptly canceled a trip to Kazakhstan and postponed a treaty signing with representatives from South Ossetia who were reportedly told not to bother to fly to Moscow. Most unusually, he was absent from an annual meeting of the top officials from the FSB, Russia’s domestic intelligence service.

The rumor mill went into overdrive, churning out possible explanations from the simple to the salacious to the sinister. He had been stricken by the particularly devastating strain of flu going around Moscow. He sneaked off to Switzerland for the birth of his love child. He had a stroke. The victim of a palace coup, he was imprisoned within the Kremlin. He was dead, age 62.

Dmitry S. Peskov, the presidential spokesman, treated all the health questions with a certain wry humor initially, coming up with new and inventive ways to say, "He’s fine."

Yet, the fact that the story proved impossible to quash underscored the uneasy mood gripping the Russian capital for months now, an atmosphere in which speculation about the health of just one man can provoke fears about death and succession.

There have been periodic glimpses of the tension behind the high red walls of the Kremlin, infighting over the wisdom of waging war in Ukraine that has only deepened as the value of the ruble crumbled under the combined weight of an oil price collapse and Western economic sanctions over the annexation of Crimea.

Those pressures seemed to culminate in the Feb. 27 assassination of Boris Y. Nemtsov, the opposition leader and former deputy prime minister who was gunned down near the Kremlin. Nemtsov’s supporters blamed the atmosphere of hate that has been brewing in Russia, with the state-controlled news media labeling him a ringleader among the "enemies of the state."

All that seemed to feed some of the darker interpretations of Putin’s disappearance. Andrei Illarionov, a former presidential adviser, wrote a blog post suggesting that the president had been overthrown by hard-liners in a palace coup endorsed by the Russian Orthodox Church. Russians could anticipate an announcement soon saying that he was taking a well-deserved rest, the post said. Conspiracy theorists bombarded Facebook, Twitter and the rest of social media with similar intrigue.

Of course, the "wag-the-dog" grandfather of all the conspiracy theories surfaced as well, that Putin disappeared on purpose to distract everyone from the problems and economic pressures piling up around them.

Given that Russia sometimes seems to be reverting to the dusty playbook of the Soviet Union, some concerns seemed to feed off old habits. In the early 1980s, when three Soviet rulers — Leonid I. Brezhnev, Yuri V. Andropov and Konstantin U. Chernenko — died in quick succession, the public was among the last to be informed.

"If an American president dies, not that much changes," said a reporter who has covered Putin for years, not wanting to be quoted by name on the subject of the president’s possible demise. "But if a Russian leader dies everything can change — we just don’t know for better or worse, but usually for worse."

The White House declined to say if it had any information about Putin’s whereabouts or whether President Barack Obama has been briefed.

"I have enough trouble keeping track of the whereabouts of one world leader," said Eric Schultz, a White House spokesman. "I would refer you to the Russians for questions on theirs. I’m sure they’ll be very responsive."

The last confirmed public Putin sighting was at a meeting with Prime Minister Matteo Renzi of Italy on March 5, although the Kremlin would have one think otherwise.

That was another aspect of the Soviet past that seemed to actually emerge from the grave: efforts to doctor the president’s timetable to confirm that all was hunky-dory.

The daily newspaper RBC reported that a meeting with the governor of the northwestern region of Karelia, pictured on the presidential website as taking place March 11, actually occurred March 4, when a local website there wrote about it. A meeting with a group of women shown as March 8 actually happened March 6, RBC said.

On Friday the Kremlin released video and still pictures of Putin meeting with the president of the Supreme Court to discuss judicial reform. The footage got heavy play on state-run television, but given that it was not live it did little to douse the flaming rumor mill.

The simplest explanation appeared to come from an unidentified government source in Kazakhstan, who told Reuters "it looks like he has fallen ill."

Since half of Moscow seemed racked with a flu that knocks people onto their backs for days at a time, that seemed the most likely explanation. (Who knows how many hands he shakes in a day?)

But there seemed to be a certain reluctance to admit that Russia’s leader, who cultivates a macho image of ruddy good health, might have been felled like a mere mortal.

His spokesman told any media outlet that called (and most did) that his boss was in fine fettle, holding meetings and performing other duties of the office.

"No need to worry, everything is all right," Peskov said Thursday in an interview with Echo of Moscow radio. "He has working meetings all the time, only not all of these meetings are public."

As new theories emerged practically by the hour, Peskov denied them all.

A Swiss tabloid reported that Putin had spent the past week accompanying his mistress, Olympic gymnastics medalist Alina Kabayeva, to give birth in a clinic in Switzerland’s Ticino canton favored by the family of the former Italian prime minister, Silvio Berlusconi. (It would be the third child, none confirmed.)

Peskov swatted that one down, too.

Of course, Putin’s opponents next door in Ukraine lost no time celebrating the possible news. One set up a clock using a joyous chorus from "Swan Lake" to count off the time since Putin last appeared alive.

One of Putin’s predecessors, Boris N. Yeltsin, used to disappear frequently as well. But that was due either to drinking bouts or, at least once, an undisclosed heart attack. His spokesman settled on a standard explanation that Yeltsin still had a firm handshake and was busy working on documents.

Peskov drolly resorted to both explanations, telling Echo of Moscow that Putin’s handshake could break hands and that he was working "exhaustively" with documents.

By Friday, Peskov’s patience appeared to be wearing thin as he told Reuters: "We’ve already said this a hundred times. This isn’t funny anymore." But he also mused aloud about finding a wealthy sponsor to underwrite a prize for the funniest hoax invented about Russia’s leader.

Early in his presidency, Putin infamously dropped out of sight when the submarine Kursk sank in 2000 and again two years later when terrorists seized a Moscow theater, trapping hundreds of hostages. But since those two crises, which spawned all manner of questions about his leadership skills, he has been very much a public figure.

A key sign that Russians seemed to be taking it in stride, despite the weird and wild tales, was that the value of the ruble barely budged. Farther away, on world markets distant from rumor central, there were gyrations attributed in part to the Putin uncertainty.

Now all eyes are on Monday, when the president is scheduled to meet with the president of Kyrgyzstan in St. Petersburg.

© 2015 The New York Times Company