Updated

Secretary General Ban Ki-Moon has condemned a bomb attack in Syria that struck close to U.N. observers, saying it could impact the mission's future.

Ban called the attack "unacceptable."

"It is a testament to the difficulty and the danger of the task entrusted to our U.N. observers, and it is a reminder of the risks of violence escalating even further," he told the U.N. General Assembly on Wednesday.

Ban said innocent civilians are still dying, government troops and heavy armor are still in city streets and there are "growing numbers of arrests and allegations of brutal torture, an alarming upsurge in the use of IEDs, and other explosive devices throughout the country."

About 70 U.N. observers are in Syria and that number is expected to reach 300 by the end of the month.

No U.N. personnel were harmed in the attack that injured 10 Syrian soldiers.