BEIRUT, Lebanon — Syrian troops advanced Wednesday on a key rebel-held neighborhood in Homs and an official vowed it would be "cleansed," raising fears of a ground operation to retake all of the central city that has become a symbol of the uprising to oust President Bashar Assad.
Government forces have been heavily shelling Homs, and particularly the rebel-controlled Baba Amr neighborhood, for more than three weeks with tanks, artillery and rockets. Three Western journalists are among 100,000 residents trapped in the siege of Baba Amr.
A Syrian official vowed early in the day that Baba Amr would be "cleansed" within hours. The official spoke on condition of anonymity in line with regulations. The announcement could portend a ground operation was beginning, but it was impossible to reach residents and activists inside to get any information.
The Obama administration summoned Syria's senior envoy in the United States to express outrage over the offensive on Homs. The State Department said its top diplomat for the Mideast, Jeffrey Feltman, met with Zuheir Jabbour, the highest ranking official at the Syrian Embassy in Washington.
Homs, Syria's third-largest city with a population of about 1 million, has become the major center of both anti-government resistance and reprisal, fueled in part by increasingly bold army defectors who want to bring down Assad's autocratic regime by force. The United Nations warned Tuesday that Syria's conflict looks increasingly like a civil war.
U.N. humanitarian chief Valerie Amos said Syria had denied her repeated requests to visit. The U.N. has appointed former Secretary General Kofi Annan as its envoy to Syria, but a Syrian official said the government has not yet decided if he can enter the country.