UN envoy in Iraq has strongly condemned the attack against the convoy of the Iraqi Parliament Speaker Osama al-Nujaifi, a UN spokesperson said here Tuesday.

Nickolay Mladenov, the Secretary-General's Special Representative for Iraq, urged all leaders to "unite against terrorism, which is affecting all segments of the Iraqi society," UN spokesperson Martin Nesirky told reporters at a daily news briefing.

The envoy called on the people of Iraq to support the security forces, local authorities and the tribes of Anbar in their fight against terrorism and to provide humanitarian support to those affected by the fighting, Nesirky said.

In addition, Mladenov urged all sides to address the causes of violence through dialogue and the political process, the spokesperson said.

A roadside bomb went off Monday near the convoy of Osama al- Nujaifi and Governor Atheel al-Nujaifi, also brother of Nujaifi, in northern Iraqi province of Nineveh, wounding two of the speaker 's bodyguards. The brothers escaped unharmed.

Iraq is witnessing its worst violence in recent years. According to the UN Assistance Mission for Iraq, a total of 8,868 Iraqis, including 7,818 civilians and civilian police personnel, were killed in 2013, the highest annual death toll in years.