BEIRUT — Supporters of President Bashar Assad pelted the U.S. ambassador to Syria with eggs Thursday as he entered an office for a meeting with a leading opposition figure and then tried to storm the building in the capital Damascus, the opposition activist said.
Ambassador Robert Ford, an outspoken critic of Assad's crackdown on the 6-month-old anti-government uprising, was trapped in the office for about three hours until Syria security forces showed up and escorted him out.
Ford came under attack as he arrived for a meeting with Hassan Abdul-Azim, who heads the outlawed Arab Socialist Democratic Union party.
Secretary of State Hillary Clinton demanded that Syria take steps to protect U.S. diplomats.
"We condemn this unwarranted attack in the strongest possible terms. Ambassador (Robert) Ford and his aides were conducting normal embassy business and this attempt to intimidate our diplomats through violence is wholly unjustified," Clinton said.
"We immediately raised this incident with the Syrian government and we are demanding that they take every possible step to protect our diplomats according to their obligations under international law."Story: Syrian uprising showing signs of armed rebellion
Ford has angered the Syrian regime in past months by visiting a couple of the protest centers outside of Damascus in a show of solidarity with the anti-government uprising. The latest incident could further raise tensions between Washington and Damascus, which has accused the United States of helping incite violence in Syria. In August, President Barack Obama demanded Assad resign, saying he had lost his legitimacy as a ruler.
Abdul-Azim said Ford was inside his office when the Assad supporters tried to force their way in, breaking some door locks. Office staff prevented them from rushing in, but the ambassador was trapped inside for about three hours with some 100 hostile pro-government protesters outside.
"Two embassy cars were damaged. The U.S. delegation is still there and the crowd is surrounding the building," a witness told Reuters.
"They are chanting 'Abu Hafez (father of Hafez)'," a nickname for Assad, the witness added.
Abdul-Azim said Syrian security arrived about an hour after the attack began.
The Deputy Chief of Mission at the US Embassy in Damascus, Haynes Mahoney, told NBC News that Ford was safe and the incident is over. He wouldn't comment on reports of egg- and stone-throwing, but told the network that the ambassador and fellow diplomats were able to leave the location once the Syrian police arrived to restore order.
The Syrian government said that once it was alerted to the confrontation, authorities "took all necessary procedures to protect the ambassador and his team and secure their return to their place of work." There was no immediate comment from the State Department in Washington.Video: Will next decade in Middle East be more volatile? (on this page)
Soon after the incident, the Syrian Foreign Ministry issued a statement accusing the United States of "encouraging armed groups to practice violence against the Syrian Arab Army."
The attack on Ford came five days after government supporters threw eggs and stones at France's ambassador as he left a meeting in Damascus with a Greek Orthodox patriarch. Ambassador Eric Chevallier was unharmed.
Tension between the West and Syria — Iran's closest Arab ally — have been rising for months.
Washington and the European Union have imposed sanctions on some Syrian officials, including Assad, because of Assad's crackdown that has left some 2,700 people, according to the United Nations.
U.S. support for protesters
A trip in July by the U.S. and French ambassadors to the central city of Hama to express support for protesters drew swift condemnation from the Syrian government, which said the unauthorized visits were proof that Washington was inciting violence in the Arab nation. Authorities then warned both ambassadors not to travel outside the capital without permission.
A month later, the Obama administration brushed off a complaint by Syrian authorities that Ford violated their travel rules by leaving Damascus without permission. The Syrian foreign ministry registered concern over Ford's trip in August from Damascus to the southern village of Jassem, where he met opposition activists.
Last month, Ford and several other ambassadors expressed their condolences to the family of a rights advocate who was killed.
The U.S. has maintained diplomatic relations with Syria even while protesting Assad's efforts to crush the uprising.
Ford arrived in Damascus in January, filling a diplomatic vacuum since Washington withdrew his predecessor in 2005. Obama had hoped the gesture would help convince Assad to reconsider his alliance with Iran and with Islamist militant groups.
Western powers are pushing for a United Nations resolution condemning Syria, although opposition from Russia and China means this is unlikely to impose immediate sanctions.
The Associated Press, Reuters and NBC News contributed to this report.