Reports on January 24 said demonstrations broke out in various regions with a significant Sunni Muslim population.

Protesters, who accuse the Shia Islamist movement of staging a coup, are blocking roads and burning tyres in several towns and cities.

Hezbollah and its allies earlier won the nomination of their candidate Najib Mikati as the next prime minister. The US expressed "great concern" over Hezbollah dominating government.

"Our view of Hezbollah is very well-known. We see it as a terrorist organisation, and would have great concerns about a government within which Hezbollah plays a leading role," State Department spokesman PJ Crowley said.

"The larger the role played by Hezbollah in this government the more problematic our relationship will be."

Lebanon's national unity cabinet collapsed on 12 January after a row over a UN tribunal investigating the 2005 murder of Mr Hariri's father, Rafik.

Saad Hariri had refused to renounce the UN inquiry that will blame senior Hezbollah figures for the murder. Hezbollah says the investigation is politically motivated.