Hezbollah’s Shiite supporters attacked a top U.S. diplomat’s motorcade with stones in southern Lebanon on Wednesday, protesting her first visit to the militant group’s stronghold, witnesses said.

In Washington, the State Department said that no one was hurt in the attack and that one local Lebanese security guard who was hit in the leg by a stone had not required treatment.

The attack occurred Wednesday afternoon after U.S. Charge d’Affaires Michele Sison visited some social and educational projects financed by the U.S. government in the southern market town of Nabatiyeh, a Hezbollah stronghold.

Sison was having lunch at the residence of Abdullah Bitar, the head of Nabatiyeh’s business organization, when about 100 Hezbollah supporters gathered outside the house and began shouting anti-U.S. slogans, according to witnesses and footage aired on Hezbollah’s Al-Manar television.

State Department deputy spokesman Tom Casey said it appeared that about 12 young men had thrown rocks at the two to three cars in Sison’s convoy. Casey said Sison then left the scene and that no one had attempted to stop her.

Al-Manar footage showed Sison, protected by bodyguards and Lebanese policemen, climbing into her vehicle.

“She was able to get in her vehicle, she was not assaulted or in any way prevented from doing so, and the convoy was able to leave and go on its route,” Casey said. “She did not have to modify her plans ... or otherwise change her schedule as a result.”

A Hezbollah official in Beirut refused to comment, saying he had no knowledge of the incident.

It was Sison’s first visit to southern Lebanon since she arrived in the country in January.

The attack came two days after Secretary of State Condoleezza Rice visited Beirut, putting an American stamp of approval on plans for a new government in Lebanon that would increase the power of Hezbollah militants.

The U.S. regards the Iranian- and Syrian-backed Hezbollah as a terrorist group and has no dealings with it.

Though rare now, attacks on U.S. diplomats and interests in Lebanon were once common.