WASHINGTON – The United States and its allies stepped up their campaign against Islamic State with 38 air strikes on targets belonging to the group in Iraq and Syria on Saturday, a joint command statement said on Sunday. Eighteen of the strikes were near the Syrian city of Raqqa, capital of the ‘caliphate’ that Islamic State has declared. The statement from the Combined Joint Task Force said tactical units and vehicles had been hit and 16 bridges had ben destroyed. The attacks in Syria also included five near Hasaka and three near Kobani, in which tactical units, vehicles and fighting positions were hit. In Iraq, Islamic State was targeted in 12 strikes near eight cities. The statement said tactical units, fighting and staging positions, weapons and vehicles had been hit.