Irish peacekeeping troops were on high alert last night after protests over the video insulting the prophet Mohammed spread to south Lebanon.
Hezbollah leader Sheikh Sayyed Hassan Nasrallah called for a series of demonstrations to be held throughout the country.
One of the areas he singled out for protest is the coastal city of Tyre, which is the route for the Irish troops from the capital, Beirut, to their area of operations in the south.
Since the Irish were re-deployed to Lebanon last year, measures for their personal protection have been much more strict than in their previous stay there.
However, there have been no serious incidents so far for the peacekeepers although their French and Italian colleagues came under a roadside bomb attack over a year ago.
With tensions rising throughout the Middle East, the troops have now increased their security level again and are taking additional precautions because of the potential for trouble.
The video, which portrayed the prophet as a womaniser and a fool, has already resulted in Lebanese protests and in the northern city of Tripoli, one person was killed and 14 were wounded in clashes with security forces.
As the leader of Hezbollah, Nasrallah heads the largest armed force in Lebanon and has a huge following among Shi'ite Muslims. The Tyre protest is due to take place tomorrow.
South Lebanon has been more stable in the past 12 months than it had been in 30 years.
This is due to the increase in the number of troops deployed there, the more robust mandate of the mission and, significantly, the co-operation by the UN with the opposition factions.