UPDATE 2-Tunisia aircraft circle after Libya attack

* Libyan troops fire several rockets into Tunisia overnight

* Tunisia has threatened to report Libya for “enemy actions”

(Releads with Tunisia response)

TUNIS, June 14 (Reuters) - Tunisia flew an F-5 warplane and a reconnaissance helicopter along its border with Libya on Tuesday, witnesses and a police source said, after Libyan troops fired several rockets into Tunisia.

Libyan troops fired Grad rockets from positions controlled by Muammar Gaddafi over the border overnight, witnesses said, in an assault likely to raise already high tensions between the two countries.

The explosions caused no damage or injuries, and are likely to have been targeted towards anti-Gaddafi rebels controlling the border with Tunisia along Libya’s Western Mountains region.

“An F-5 plane and a helicopter were patrolling at the border with Libya to survey the situation after the rockets fell on the region of Mrabeh,” a police source in the area told Reuters by telephone.

Two witnesses in the border region also said they saw the aircraft circling in the sky overhead. “At least five rockets fell on Tunisian soil today in the Mrabeh. It was a heavy bombardment from Gaddafi’s side of the mountains,” said resident Mohammed Nagez, a local trader.

Another local police officer, who could not be named, said Tunisian security forces feared the rockets might hit the main border crossing at Wazen, where thousands of people are often gathered at any one time.

The last time Libyan forces fired rockets into Tunisia, on May 17, the Tunisian government threatened to report Libya to the U.N. Security Council for committing “enemy actions”. (Writing Tim Cocks; Editing by Jan Harvey)