Hundreds of Syrians have fled across the border into neighboring Lebanon to escape escalating violence in their homeland.

A Lebanese security official said Saturday that up to 1,000 Syrians, at least six with gunshot wounds, have crossed into northern Lebanon over the past two days near the border town of Wadi Khaled. The injured refugees are receiving treatment in Lebanese hospitals.

The new arrivals join thousands of other Syrians who entered Lebanon in May and early June.

The latest group of refugees fled shortly after Syrian security forces opened fire on anti-government protesters Friday. A Syrian rights group that collected reports from around the country said at least 20 people were killed, including two children. Most of the deaths are said to have occurred in or around the capital, Damascus.

Witnesses and activists said tens of thousands of protesters gathered in various locations Friday despite a heavy security presence and fears of the continuing crackdown.

The military's recent sweep through northwestern Syria, where armed resistance flared in early June, also has sent more than 12,000 refugees into Turkey, where there are now huge encampments of Syrian refugees.

Turkish officials said Friday that more than 1,500 Syrian refugees crossed the border after government troops stormed the town of Khirbet al-Jouz.

Syrian troops were said to be within 500 meters of the Turkish frontier Friday – their closest approach to Turkish territory since military operations in the area began two weeks ago. Turkish troops moved their border positions several hundred meters back to avoid potential confrontations with Syrian units.

Demonstrators in Syria attempting to overthrow President Bashar al-Assad have been under assault by pro-government forces for more than 100 days.

In the Damascus suburb of Irbin , protesters shouted, “Tell the world Bashar is without legitimacy.”

Syrian state television claimed “armed gangs,” not government forces, killed three people in one Damascus suburb.

Details of the latest violence could not be independently confirmed because Syria allows very few foreign news reporters into the country, and such visitors do not have full freedom of movement. Activists say Syria's crackdown has killed at least 1,400 people in the last three months.