Updated

BEIRUT -- Syrian troops pounded a central town with artillery and gunfire Thursday, renewing attacks in a restive area that has been largely cut off from outside contact for six days. At least 15 people died, bringing the total killed there to 72 since the onslaught began, activists said.

What started as street demonstrations calling for reforms evolved into demands for President Bashar Assad's ouster in the face of the violent crackdown, especially in Syria's south and center, where the challenge to his family's 40-year-rule is seen as strongest.

Activists say more than 1,100 people have died in the crackdown and 10,000 have been detained. But it hasn't slowed the protests, which take place nearly daily and swell into the thousands each Friday.

A resident of Rastan, a protest stronghold in central Syria, said the town's electricity was cut and it was by tanks. He said troops bombed the water supply as well as a mosque and the sports complex.

"We have become refugees in our own country," said the man reached by telephone, who said he fled his home in the town center to escape arrest and was sleeping in the woods.

"My family and sisters are still there, and I don't know how they are doing," he said, speaking on condition of anonymity for fear of reprisals.

He said army units entered some neighborhoods Wednesday evening and were making arrests.

Members of Syria's fragmented opposition meeting in Turkey on Thursday called on Assad to step down and vowed to work together to lobby world leaders for a U.N. Security Council decision calling for his trial.

Mohammad Abdullah, an exiled Syrian journalist, told The Associated Press by phone from Antalya that the meeting's closing statement urged Assad to hand power to his vice president and hold free parliamentary and presidential elections within a year.

The conference also elected a 31-member council to coordinate support for the protests in Syria, lobby world leaders and document state violations during the uprising.

Assad's government has shown no signs of relenting and got a strong signal of support on Thursday from Russia, a close ally. In Washington, Secretary of State Hillary Rodham Clinton appeared to have Russia, China and some Arab countries in mind as she said nations slow to denounce the Syrian crackdown should get on what she called "the right side of history."

The Syrian government on Wednesday freed hundreds of political prisoners in an amnesty and the president set up a committee for national dialogue in an effort to end the 10-week uprising, but concessions have been coupled with deadly attacks on the towns seen as the greatest threat to his power. Electricity and telephone lines were cut Saturday in Rastan and some nearby towns, and the government attacks have been constant ever since, activists say.

Such concessions would have been unimaginable only months ago, but protesters have already rejected the amnesty as too little, too late.

"The one who needs the amnesty is the killer," said Molham Aldrobi, a representative of Syria's outlawed Muslim Brotherhood who attended the conference in Antalya, Turkey.

The Local Coordination Committees, which help organize and document Syria's protests, said a 4-year-old girl was among the most recent deaths in the town of Rastan, where a total of 58 have been killed in the past three days. The nearby towns of Talbiseh and Teir Maaleh, which like Rastan have seen persistent protests, have also come under attack.

There were no reports of protests on Thursday in Homs but the Syrian opposition called for nationwide demonstrations on Friday, the Muslim day of prayer, to commemorate the nearly 30 children killed in the uprising.

The images of children who activists say were killed during the government crackdown have circulating widely among Syrians on YouTube, Facebook and opposition websites, shocking the public and stoking even more fury against a regime the opposition says has lost all legitimacy.

Syria's state-run Tishrin daily criticized the meeting in Turkey saying those who are participating in the conference only have one thing in common which is "dependence on foreign countries to interfere in Syria's internal affairs, destabilize it and undermine its security."

Russian Foreign Minister Sergei Lavrov also issued a warning to protesters, saying that attempts to change Assad's regime by force will have "catastrophic consequences."