BEIRUT (AP) — Lebanon's president postponed talks Monday on naming a new prime minister after the only candidate — caretaker Prime Minister Saad Hariri — failed to win the backing of the country's largest Christian groups amid a worsening economic and financial crisis.

The postponement followed a violent weekend in the tiny Mediterranean nation that saw the toughest crackdown on demonstrations in two months.

Lebanese security forces repeatedly fired tear gas, rubber bullets and water cannons to disperse hundreds of protesters in downtown Beirut in the worst violence since demonstrations against the political elite erupted in mid-October.

President Michel Aoun was to meet with the heads of parliamentary blocs to discuss the naming of the new prime minister. Those consultations are binding according to the constitution, and Hariri, who resigned under pressure on Oct. 29, was widely expected to be renamed.

The presidential palace said the consultations would occur instead on Thursday, based on a request from Hariri. Aoun similarly postponed talks with the heads of parliamentary blocs last week amid deep divisions among the various factions.

The U.N. Special Coordinator for Lebanon Jan Kubis had warned that because of the collapsing economy, such postponements were “a risky hazard both for the politicians but even more so" for the people.

Lebanon is enduring its worst economic and financial crisis in decades with a massive debt, widespread layoffs and unprecedented capital controls imposed by local banks amid a shortage in liquidity.

Hariri resigned after protests began earlier in October over widespread corruption and mismanagement. The palace said Hariri had asked Aoun to allow for more time for discussions among political groups before official consultations.

Earlier, the country's main Christian groups said they refused to back Hariri, who has served as premier three times. The Lebanese Forces Party, with 15 seats in the 128-member parliament, said it won't name anyone, while the Kataeb Party said it will propose former U.N. Ambassador Nawaf Salam for the post.

Aoun's Free Patriotic Movement and allied parties, which have the largest bloc in the legislature, also were not likely to name Hariri amid sharp divisions between Hariri and the party's chief, outgoing Foreign Minister Gebran Bassil. Hariri apparently is trying anew to persuade Christian parties to back him.

His office said in a statement that he is keen for national accord, adding that had he been named to the post, it would have been “without the participation of any of the large Christian blocs."

Under Lebanon's power-sharing system, the prime minister has to be a Sunni Muslim, the president a Maronite Christian and the parliament speaker from the Shiite community. Hariri has emerged as the only candidate with enough backing for the job, but he is rejected by protesters who demand a Cabinet of independent technocrats and an independent head of government not affiliated with existing parties.

“Saad, Saad, Saad, don't dream of it anymore!” protesters chanted Sunday.

Security forces used tear gas, rubber bullets and water cannons to disperse protesters for a second straight day, ending what started as a peaceful rally. Unknown assailants also set fire to two tents set up by protesters in Martyrs' Square in Beirut, the epicenter for the anti-government rallies.

After hours of clashes, the army was deployed around central Beirut, putting an end to the street battles. Dozens of people were injured, most of them only slightly hurt.

Although the protests had united all sectarian and ethnic groups against the ruling elite, tensions had surfaced from the start between protesters and supporters of the Shiite groups Hezbollah and Amal, after the latter rejected criticism of its leaders.

Hariri had asked the International Monetary Fund and the World Bank for help developing a reform plan to address the economic crisis.

Moody's Investors Service said that without technical support from the IMF, World Bank and international donors, it was increasingly likely that Lebanon could see “a scenario of extreme macroeconomic instability in which a debt restructuring occurs with an abrupt destabilization of the currency peg resulting in very large losses for private investors.”

Its currency has been pegged at 1,507 Lebanese pounds to the dollar since 1997, but in recent weeks it has reached more than 2,000 in the black market. Lebanon's debt stands at $87 billion or 150 percent of GDP.