Syrian forces launched a renewed assault on the flash point city of Hama on Monday, extending their effort to crush a four-month-old rebellion into the first day of the Muslim holy month of Ramadan despite growing world condemnation.

At least nine people were killed Monday, according to the human rights group Insan, four of them in Hama. The other five were killed in the two eastern towns of Deir el-Zour andAbu Kamal, which also have been targeted by the regime in its offensive to suppress the uprising and by the opposition to escalate anti-government demonstrations during Ramadan.

But the toll in Hama was expected to rise because residents reported a sudden and intense increase in the scale of bombardments against the city Monday night, with shells crashing into residential neighborhoods, a hospital and the courthouse.

Activist Saleh Hamawi, reached by telephone, said it was impossible to know exactly what was happening because of the darkness and the intensity of the fire. “The bombing is very big, and they are using some bombs that are bigger than tanks,” he said, adding that he knew of several casualties but could not specify a number.

The offensive suggests that the government of President Bashar al-Assad has not been swayed by sensitivities surrounding deaths in the holy month, during which observant Muslims fast between sunrise and sunset. In the attack Sunday, 102 people died, 76 of them in Hama, Insan reported.

Troops did not, however, penetrate the center of the city, which has effectively been under the control of protesters since early June, turning Hama into a beacon of hope for other areas in the country struggling to stage anti-government demonstrations in the face of harsh suppression. Hama is also considered uniquely sensitive because it is the site of an infamous massacre in 1982 in which at least 10,000 people died when Assad’s father, Hafez, crushed an uprising there.

Activist Omar Habbal, also contacted by telephone, said unarmed residents were continuing to stand at barricades erected to keep troops out and would remain there despite the renewed bombardments.

“They are showing the military that we will defend our city to the last child,” he said. “We will never give up, and they won’t be able to enter the city.”

U.S. Ambassador Robert Ford visited Hama early last month in a gesture of support for the protesters and reported later that he could confirm that they were not armed.

Yet, although world governments lined up to condemn the escalating violence in Syria, there was little indication of any imminent concrete action to increase pressure on Assad. There are continued concerns within the international community that his departure could trigger regionwide instability and civil war.

The Obama administration said it was studying unspecified new sanctions and unilateral measures and reiterated its condemnation of the violence, with State Department spokesman Mark Toner calling the attacks “despicable and abhorrent.”

“We’ve done a great deal already,” Toner said. “We’re looking at other steps. These can’t be enacted overnight.”

Three senators repeated their call that President Obama take much tougher action, including to call outright for Assad’s departure, a step that U.S. officials fear would commit them to escalating involvement in an internal conflict.

“It is beyond any shred of doubt that Assad and his regime are unwilling to reform and intend to use violence to beat the Syrian people into submission,” said a statement signed by Sens. John McCain (R-Ariz.), Joseph I. Lieberman (I-Conn.) and Lindsey O. Graham (R-S.C.).

Ford, who is in Washington for a Senate confirmation hearing Wednesday, met with Obama for consultations, the White House said. State Department officials said they were monitoring events in Syria to determine whether Ford’s U.S. visit should be cut short to enable him to return to Damascus.

The European Union extended financial sanctions and travel bans to five additional members of the Assad regime but rejected the imposition of more forceful energy sanctions, saying they would also harm ordinary Syrians.

Germany formally requested an emergency meeting of the U.N. Security Council to address the situation in Syria, but objections by Russia and China to international intervention in a country with which they have warm ties have forestalled any action at the United Nations.

Neighbor Turkey, which has played a leading role in trying to exert pressure on the Syrian government to implement reforms, repeated its call for changes but suggested no new steps. Turkish President Abdullah Gul said he was “horrified” by the violence.

“The use of heavy weapons in Hama against civilians has given me a deep shock,” he said, according to the state-run Anatolia news agency.

Warrick reported from Washington.