AMMAN, Jordan – A car bomb ripped through Syria’s largest city, Aleppo, on Sunday, killing at least 17 people and wounding 40 in one of the main battlegrounds of the country’s civil war, state-run media said.

Al-Qaida-style bombings have become increasingly common in Syria, and Western officials say there is little doubt that Islamist extremists, some associated with the terror network, have made inroads in the country as instability has spread. But the main fighting force looking to oust President Bashar Assad is the Free Syrian Army, a group made up largely of defected Syrian soldiers.

Sunday’s blast came hours after a Jordanian militant leader linked to al-Qaida warned that his extremist group will launch “deadly attacks” to help the rebels in Syria topple Assad.

In a speech delivered to nearly 200 followers protesting outside the prime minister’s office in Amman, Mohammad al-Shalabi, better known as Abu Sayyaf, told Assad that “our fighters are coming to get you.”

The warning fueled concern that Syria’s civil war is providing a new forum for foreign jihadists, who fought alongside Iraqi Sunni insurgents after the 2003 invasion of Iraq and are sending fighters to help the Taliban in Afghanistan.

A Jordan-based Western diplomat who monitors Syria said the number of foreign fighters is about 100 and gradually rising. He spoke on condition of anonymity, saying identifying him could risk his ability to gather information on Syria.

Fighting also raged elsewhere in Syria, with at least 58 people reported killed and scores wounded, according to the Syrian Observatory for Human Rights