At least 43 people were killed by a car bomb on Thursday at the Bab al-Salameh border crossing between Syria and Turkey.
The Syrian Observatory for Human Rights said that over 80 people suffered injuries at the rebel-held border crossing, reports The New York Times. The car bomb attack was said to be from the Islamic State of Iraq and Syria, according to Aleppo Media Center's Mohammad Wissam.
Many claim that ISIS is backing, or at least appears to be, the Syrian government as their focus is less on ousting President Bashar al-Assad and more establishing Islamic rule in the country.
According to The Associated Press, the border crossing was captured about a year into the three-year civil war and has provided insurgents with an excellent point to get people and supplies into the country. Clashes around the crossing have increased over the past month.
The fighting between the two sides has resulted in over 150,000 people being killed and millions more displaced. Al-Assad's government has been trying to drive back rebels near the government's capital of Damascus as the upcoming election nears.