The Syrian army has instigated the bloodshed in the besieged city of Homs by launching attacks on civilians, according to the United States ambassador to Syria.

Ambassador Robert Ford wrote in a Facebook note that video and photos emerging from Homs offered clear proof that the Syrian army was bombarding residential areas with artillery, violating the terms of an Arab League protocol the Syrian government signed in December. Ford dismissed suggestions that armed dissidents were responding with the same level of force.

It is odd to me that anyone would try to equate the actions of the Syrian army and armed opposition groups since the Syrian government consistently initiates the attacks on civilian areas, and it is using its heaviest weapons, Ford wrote.

The Syrian government has pushed a different narrative, maintaining that the uprising is caused by terrorist groups financed by foreign governments. The New York Times noted that the state-run television channels in Russia and Iran, both allies of Syria, advance the same explanation -- one correspondent said that massive explosions in Aleppo were directed from London, Tel Aviv, Paris and New York -- and a report by Human Rights Watch found that army defectors believed they were fighting terrorists until they were forced to fire upon civilians.

The United States has halted operations at its embassy in Syria, and Ford wrote that being evacuated along with fellow diplomats was the most emotionally taxing day of my career. He noted that the Syrian government has rebuffed the embassy's request for additional security measures.

I left Damascus with immense sadness and regret-I wish our departure had not been necessary, but our Embassy, along with several other diplomatic missions in the area, was not sufficiently protected, given the new security concerns in the capital, Ford wrote