Islamic State fighters seized a Syrian town back from Kurdish-led forces near Raqqa city on Monday, a group monitoring the war reported, recovering ground near its de facto capital two days after it was pummelled in heavy U.S.-led air strikes. The Syrian Observatory for Human Rights said Islamic State forces had taken Ain Issa and surrounding areas from the YPG militia, which only seized the town from Islamic State control two weeks ago.A spokesman for the YPG could not immediately be reached for comment, but had earlier reported an attack by large numbers of Islamic State fighters on YPG positions in the area about 50 km (30 miles) north of Raqqa city.U.S. officials said the air strikes in Raqqa city over the weekend were some of the most intense to date against Islamic State in Syria.The Observatory said the attacks destroyed seven bridges over waterways in the city, which is bordered to the south by the Euphrates river, in a bid to curtail Islamic State's ability to move fighters and equipment.Ain Issa, the town reportedly recaptured on Monday, sits on a major east-west highway that runs all the way from Aleppo in the west to the Iraqi city of Mosul.The YPG-led forces captured Ain Issa on June 23, part of an offensive that drove deep into Islamic State's stronghold of Raqqa province. The YPG also captured the town of Tel Abyad at the Turkish border in the offensive. ..