ISIS stages surprise attack on key Syrian border town

BEIRUT -- Activists say fighters with the Islamic State of Iraq and Syria (ISIS) have launched a surprise attack on a Syrian border town recently taken over by U.S.-backed Kurdish forces.

Kurdish activist Mustafa Bali and Rami Abdurrahman of the Syrian Observatory for Human Rights, a monitoring group, say ISIS fighters attacked Tal Abyad on the Turkish border on Tuesday, entering from the east.

Bali says fierce gunbattles raged for up to three hours between the two sides before the ISIS fighters took shelter in an empty school building.

Kurdish forces drove ISIS fighters out of Tal Abyad earlier this month, depriving the extremist group of a key point for bringing supplies and foreign fighters into Syria.

CBS News correspondent Holly Williams reported that more than 20,000 people fled the town as airstrikes targeted ISIS positions, a desperate escape for people who've lived under the extremists for over a year.

"If a woman went out without veiling her face, or a man smoked a cigarette, they'd beat them with a stick," one woman told CBS News, covering her face to hide her identity because she's still frightened of ISIS.

She and her friends said they grew used to seeing severed heads displayed in the street, left there as a warning after ISIS carried out executions.