Pro-Iranian militias have entered Syria from Iraq to provide support to the Syrian army in their battle against insurgents. The militias, including Iraq's Katiab Hezbollah and Fatemiyoun groups, crossed into Syria through a military route near Al Bukamal crossing. Iran has previously sent thousands of Shiite militias to Syria, along with Russian air power, to help President Bashar Assad regain control of the country. The lack of manpower in recent days has contributed to the retreat of Syrian army forces and the withdrawal from Aleppo city. Israel has also increased its strikes on Iranian bases in Syria and launched an offensive in Lebanon to weaken Hezbollah.