Lebanon's divided politicians rarely agree on anything, but they have fleetingly united in calling for resigned Prime Minister Saad Hariri to return home, even if their motivations vary vastly.

Hariri announced his resignation on November 4, in a shock statement delivered from Saudi Arabia on the kingdom's Al-Arabiya television station.

The resignation, which reportedly took even his closest advisers by surprise, as well as his decision to announce it from abroad, quickly led to speculation about whether he had been forced to step down by Riyadh.

Then, a massive wave of arrests of high-profile figures within Saudi Arabia led to swirling rumours about whether Hariri too was being held against his will.

Hariri's detractors, including the powerful Hezbollah movement and its allies, have used the speculation to paint him as feeble and at the mercy of his Saudi sponsors.

On Wednesday, President Michel Aoun, a political rival of Hariri's despite the deal they made to form a government, directly charged Riyadh with having "detained" the Lebanese premier.

"Nothing justifies the failure of Prime Minister Saad Hariri to return for 12 days, therefore we consider him to be held and detained, contrary to the Vienna Convention," Aoun said in a tweet on the official Lebanese presidency account.

Aoun is an ally of the powerful Hezbollah movement that has long been a thorn in Hariri's side, and the group's leader Hassan Nasrallah has also suggested the premier was being held.

- Imminent return? -

Hariri's own Future Movement has called his return its "top priority."

Hariri tried to put paid to suggestions he was being held against his will in an interview with his party's Future TV on Saturday.

"I am free here. If I want to travel tomorrow, I will," Hariri said.

"I will return to Lebanon very soon," he added, pledging to land in Beirut "in two or three days".

But he has yet to return, and pronouncements from France and other countries have suggested he may not have the freedom of movement he professes.

In tweets on Tuesday and Wednesday, he renewed his promise to return, but there was little sign many Lebanese expected his arrival imminently.

On the ground, conversation among Lebanese has been consumed by the whereabouts of their erstwhile prime minister and the possibility of his return.

Treatment of the subject has ranged from earnest to satirical, with hashtags and memes circulating on social media as debate rages on the issue.

Soon after his resignation, the hashtags #WhereisSaad? and #freeSaad began to circulate on social media, and a website -- freesaadhariri.com -- was set up tracking the minutes since he stepped down.

Over the weekend, runners in Beirut's 15th annual marathon sported tshirts and signs declaring "We want our PM back."

And across parts of the capital, posters have gone up in solidarity with the missing premier, featuring his face and slogans like "We are all with you."

- Anger and laughter -

Nawal, a resident of Beirut's Ras al-Nabaa neighbourhood in her fifties, was fuming at what many in the country, regardless of sectarian or political allegiance, have perceived as a humiliation.

"We're very upset about what happened to him. We didn?t think Saudi Arabia could treat a Lebanese like this. We want Saad Hariri to return immediately because what happened has made us very angry," she said.

In a country that has lived through decades of political turmoil and unrest even since the end of the 1975-1990 civil war, there is still enough sangfroid however to joke about the situation.

One widely circulated meme showed a crop of Lebanese politicians in military helmets on a parody poster of the movie "Saving Private Ryan."

"Saving Private Saad" reads the caption below them.

In another instance, the word "HELP" was edited onto the face of Hariri's wristwatch.

But not everyone has found the events so amusing.

"The sad fact is that the joke is really on us," wrote Najib Mitri on the BlogBaladi website.

"This is humiliating to all of us Lebanese."

And Lebanon's newspapers have been full of editorials warning that the crisis bodes ill for a country that has been buffeted by regional conflicts including the rivalry between Saudi and Iran, and the war in neighbouring Syria.

"What is most disturbing... is the fact that people are ignoring building clouds of danger," wrote editorialist Nabil Bou Monsef in the An Nahar newspaper.

"Someone has decided that they are capable of destroying their regional rival... even if it comes at the cost of a new crisis for Lebanon."