Security was tight in Lebanon on Wednesday as several schools remained closed but traffic returned to normal following a "day of rage" over the appointment of a premier from the opposition.

A heavy army presence could be seen across the country as shops re-opened, but several international schools remained closed fearing another outbreak of demonstrations.

Anti-riot troops patrolled the streets of Beirut and the northern port city of Tripoli, a Sunni bastion and hometown of prime minister designate Najib Mikati who had been nominated for premiership by the opposition which includes Hezbollah.

Banners reading "Mikati, appointed by Khamenei," Iran's supreme leader, remained hoisted in Tripoli on Wednesday as tanks were deployed outside Mikati's home and offices.

Residents of Tripoli said they also planned to set up a tent in a city square around noon to protest his appointment.

Demonstrations against Mikati's appointment turned violent on Tuesday as protesters burned tyres and temporarily blocked main highways.

Frenzied demonstrators in Tripoli torched an Al-Jazeera van, while in the capital, stone-throwing and baton-wielding protesters attacked media considered close to Hezbollah.

Supporters of outgoing prime minister Saad Al-Hariri, backed by Saudi Arabia and the United States, claim Mikati's appointment is a bid by the Shia group to impose their choice for the premiership, a post reserved for a Sunni Muslim. Hezbollah's chief Hassan Nasrallah denied such claims maintaining the group does not seek to control the government.

His appointment came after Hezbollah and its allies toppled Hariri's government in a long-running dispute over a UN court probing the 2005 murder of ex-premier Rafiq Al-Hariri, Saad's father.

The Netherlands-based Special Tribunal for Lebanon is reportedly readying to indict Hezbollah affiliates in connection with the Hariri murder, a move the group has warned against considering it an American-Israeli plot.

The United States accused Hezbollah on Tuesday of using intimidation to gain government control in Lebanon and vowed that the work of the UN-backed Hariri tribunal would continue regardless.

"The make-up of Lebanon’s government is a Lebanese decision, but this decision should not be reached through coercion, intimidation and threats of violence," State Department spokesman Philip Crowley said in a statement. "Unfortunately, Hezbollah, backed by Syria, engaged in all three in pursuit of its political goals."

US Secretary of State Hillary Clinton said earlier that the fact that Lebanon's government was now Hezbollah-controlled would "clearly have an impact" on ties with the United States.

The United States considers Hezbollah a terrorist group.