UN-Arab League envoy Kofi Annan said on Tuesday that Iran should be "part of the solution" to the Syrian conflict, after talks in Tehran with the Iranian foreign minister.

The talks came as dozens of shells fired from Syria landed in northern Lebanon, where thousands of Syrians have sought refuge from the 16-month-long uprising, fuelling fears that the conflict may spill over into the neighboring country.

"My presence here (in Tehran) proves that I believe Iran can play a positive role and should therefore be a part of the solution in the Syrian crisis," Annan told reporters at a joint press with Foreign Minister Ali-Akbar Salehi.

The United States and the European Union have objected to allowing Iran, a staunch ally of Syrian President Bashar Assad, to play a role in resolving Syria's 16-month long conflict. Annan said that he could only speak for himself.

According to a UN source, Annan believes that the Iranian role is essential in defusing the crisis, and that Tehran "can use its good offices with the Syrian leadership to reach a solution to end the violence."

The primary aim in Syria should be containing the violence, Annan said, "collecting arms which are in the wrong hands" and putting a swift end to further militarization of the crisis.

He declined to give further details about his talks with Assad on Monday, which he said afterwards had been "constructive." The violence should stop in order to enable talks to begin between the conflicting sides, he said.

At the weekend Annan admitted that his six-point peace plan for Syria, based on a ceasefire which never held, had failed.

Annan was also to meet with Saeid Jalili, secretary of Iran's National Security Council. It was unclear whether he would also meet President Mahmoud Ahmadinejad.

In Lebanon, the new wave of violence prompted many residents in the area of Wadi Khaled to flee to safer areas. The latest incident came two days after border clashes during which three women were killed and several wounded in Lebanon.

Syrian state media said that their forces were chasing rebels who tried to infiltrate Syria from Lebanon.

The Lebanese cabinet decided Monday to boost their army presence along the border with Syria to avoid further escalation.

Violence continued across Syria, mainly in the restive areas of Homs, and the northern province of Idlib, activists said.