More than a thousand Syrian refugees have poured across the border into Lebanon, among them families with small children carrying only plastic bags filled with their belongings as they fled a regime hunting down its opponents.

The U.N. refugee agency said Monday that as many as 2,000 Syrians had crossed into Lebanon in the last two days. Associated Press reporters in one border village saw families crossing with only a few possessions.

"We fled the shelling and the strikes," said Hassana Abu Firas in Qaa in northeast Lebanon. She came with two families who had fled government shelling of their town al-Qusair. The town is in Homs province, an opposition stronghold where the government has been waging a brutal offensive for the past month. The province borders Lebanon.

"What are we supposed to do? People are sitting in their homes and they are hitting us with tanks. Those who can flee flee and those who can't will die sitting down," she said.

Homs, the provincial capital and Syria's third-largest city with one million residents, has emerged as a central battleground in the year-old uprising to oust authoritarian President Bashar Assad.

Activists say hundreds have been killed in the month-long Homs offensive and the U.N. recently put the death toll for a year of violence in Syria at 7,500. However, activists group say the toll has already surpassed 8,000.

The crackdown in Homs also killed an American reporter and a French photographer who sneaked into the country and filed their final reports shedding light on the horrors of life under assault and the quickly swelling humanitarian catastrophe in the city.

During the Homs offensive, international condemnation of the Assad regime grew more intense by the day. The U.S. has called for him to step down, and Secretary of State Hillary Rodham Clinton said he could be considered a war criminal. The European Union said it would document alleged war crimes in Syria to set the stage for a "day of reckoning" for the country's leadership, in the way that former Yugoslav leaders were tried for war crimes in the 1990s by a U.N. tribunal.

The hardest hit district of Homs is Baba Amr, an area that had been held by rebels for several months before regime forces drove them out on Thursday. On Monday, the Red Cross said it had received permission to enter Baba Amr, but had not entered yet.

The Red Cross has been distributing aid around other parts of Homs for the past two days, but the regime has blocked it from entering Baba Amr since relief workers arrived in the area on Friday. Activists alleged that after the Syrian forces seized back control of Baba Amr, they killed dozens of residents execution-style and burned homes in revenge attacks against those believed to be supporting the rebels.

The Syrian government claims it has been blocking access to Baba Amr out of security concerns.

As the neighborhood remained cut off, concerns mounted over the desperate plight of civilians facing severe cold and hunger, and the reported revenge attacks.

Homs activist Mulham al-Jundi accused Syrian forces of keeping aid teams out of Baba Amr to hide their activities there. He said he heard a few explosions in the neighborhood and saw columns of smoke there from a rooftop elsewhere in the city.

"We have heard explosions in Baba Amr, so it seems that they are destroying some of the houses and important centers there," he said via Skype.

The head of the Syrian Red Crescent in Homs province, Shueib Shaaban, said aid teams would enter part of the area Monday. Shaaban said authorities said the group could enter all of Baba Amr on Tuesday and that the group was sending three trucks with aid for the neighborhood.

The Red Cross has said the greatest needs are food, medical supplies and blankets, due to frigid temperatures and snowfall.

The violence in Homs sent many families fleeing into nearby neighborhoods and villages, and the Red Cross distributed milk powder, medicine, food and blankets on Sunday to some 400 displaced families in the Abel village south of the city, Shaaban said. That aid continued Monday.

Syria blames the uprising on Islamist extremists and armed gangs seeking to destabilize the country. Syrian state TV showed municipal workers sweeping the streets in Homs and clearing barricades and ruins -- part of what it called a long process of repairing infrastructure damaged by armed groups.

Though the crisis in Syria has left Assad increasingly isolated internationally, he still can count on a few powerful allies.

Russia and China have stood by stood by Assad, rejecting all forms of interference in Syria's affairs and protecting Syria from condemnation by the U.N. Security Council. Both countries fear such a move could pave the way for military intervention against Assad, as it did against Muammar Qaddafi in Libya.

Syria on Monday lauded the return of Vladimir Putin to the Russian presidency, saying his "strong man" status would reshape international relations.

Also Monday, China said it would send its former ambassador to Syria to try to convince the Assad regime of the need for a cease-fire, and to emphasize its opposition to outside intervention.

Li Huaqing will visit Damascus on Tuesday and Wednesday, the Foreign Ministry said.

China's own proposal for ending the Syria conflict calls for an immediate an immediate cease-fire and talks by all parties.