Turkish stocks headed for the lowest close this year and the lira weakened after a car-bomb attack at a crossing on the border with Syria killed at least 10 people.

The Istanbul Stock Exchange National 100 Index tumbled 1.6 percent to 77,438.34 points at 4:59 p.m. in Istanbul, poised for the lowest close since Dec. 24. The lira retreated 0.3 percent to 1.7769 per dollar, the lowest in a month.

Dozens were wounded in the blast at the Cilvegozu border point, according to a report by the state-run Anatolia news agency. Turkey has supported Syrian rebels in their fight to topple President Bashar al-Assad.

“The blast hit market sentiment,” Mehmet Gerz, the chief executive officer of Istanbul-based Ata Invest, said by phone. “What concerns investors is the possibility that Turkey might be dragged into the turmoil in the region.”

To contact the reporter on this story: Taylan Bilgic in Istanbul at tbilgic2@bloomberg.net

To contact the editor responsible for this story: Claudia Maedler at cmaedler@bloomberg.net