Lebanese President Michel Suleiman has condemned a Syrian air strike on Lebanon's side of the border between the two countries, calling it an "unacceptable violation" of Lebanese sovereignty.

The president's comments on Tuesday were a rare rebuke of Syria, a powerful, larger neighbour that once dominated

Lebanon.

Syrian air force jets fired four rockets at a remote section of the border with Lebanon on Monday, security sources said, four days after Damascus warned it may strike at Syrian rebels taking refuge across the frontier.

Many residents of the border town of Arsal back the uprising against Syrian President Bashar al-Assad.

Local residents said the missiles had fallen in an agricultural area and there were no injuries in the incident. There are an estimated 15,000 Syrians taking refuge in Arsal.

Al Jazeera's Rula Amin, reporting from Arsal, said the local residents were very concerned of the attack, fearing more strikes.

"It's a very serious development," our correspondent said. "Most Lebanese politicians were very alarmed by this airstrike."

But in a statement on state television, Syria's foreign ministry said the country "stresses its respect for Lebanese sovereignty and its support for Lebanon's security and stability".