More than 250 Italian troops have landed in south Lebanon as part of efforts to monitor the ceasefire in the south of the country.
The marines, wearing blue UN berets, came ashore in the port of Tyre in helicopters and rubber dinghies from an Italian aircraft carrier.
An Italian navy spokesman said some 800 had arrived in Lebanese waters out of a total of about 3,000 that Italy has pledged.
The rest of the 800 will land later today and tomorrow, depending on sea conditions.
Italian ships are simultaneously unloading military vehicles at the small UN port at Naqoura, about 20km south of Tyre, the Italian spokesman said.
The UN Peacekeeping Chief, Jean Marie Guéhenno, said his troops were prepared to take action if there were acts of violence but he was optimistic that there was enough political will on both sides to bring an end to the conflict.
The Italians will make up the largest single contingent to the new force, known as UNIFIL II, which will deploy along the Israeli-Lebanese border after a one-month conflict between Israel and Hezbollah.
A truce came into effect on 14 August and has held with few violations other than flights over Lebanon by Israeli planes, defying widespread expectations of intermittent violence.
The UN Security Council fixed the target size of the force at 15,000 and the United Nations has already recruited more than half that number.
Adding to the 3,000-strong Italian contribution, France have offered 2,000 troops and Spain more than 1,000. Poland, Indonesia and Belgium have also said they are willing to take part.
