Islamic State fighters launched simultaneous attacks against the Syrian government forces and Kurdish militia, moving back onto the offensive after losing ground in recent days to Kurdish-led forces near the capital of their "caliphate". After losses to the Kurds backed by U.S.-led air strikes, Islamic State sought to retake the initiative with incursions into the Kurdish-held town of Kobani at the Turkish border and government-held areas of Hasaka city in the northeast. In a separate offensive in the multi-sided Syrian civil war an alliance of rebels in the south of the country also launched an attack with the aim of driving government forces from the city of Deraa. The attacks by Islamic State follow a rapid advance by Kurdish-led forces deep into the hardline group's territory, to within 50 km (30 miles) of its de facto capital Raqqa, hailed as a success by Washington. The dual assaults on government forces in Hasaka and Deraa - both provincial capitals - are a test of Assad's resolve to hold out in remote outposts beyond the western area of the country seen as the top priority for his survival. The United States and European and Arab allies have been bombing Islamic State since last year to try and defeat a group, which a year ago proclaimed a caliphate to rule over all Muslims from territory in Syria and Iraq. Islamic State advanced rapidly last month, seizing cities in Syria and Iraq. The latest Kurdish advance in Syria has shifted the momentum again but Islamic State fighters have often adopted a tactic of advancing elsewhere when they lose ground. The group said it had seized al-Nashwa district and neighboring areas in the southwest of Hasaka, a city divided into zones of government and Kurdish control. Government forces had withdrawn toward the city center, it said in a statement. Syrian state TV said Islamic State was expelling residents from their homes in al-Nashwa, executing people and detaining them. Many Islamic State fighters had been killed, it said, included one identified as a Tunisian leader. The Syrian Observatory for Human Rights, which tracks the war, said Islamic State had seized two districts from government control. Government-held parts of Hasaka are one of President Bashar al-Assad's last footholds in the northeast region bordering Iraq and Turkey, territory mainly run by Kurds since Syria's conflict erupted in 2011. The Kurdish militia say they currently have no plan to march on Raqqa city. In Syria's south, rebels launched an assault to capture Deraa, which, if it falls, would be the third provincial capital lost by Assad in the four-year-long war, after Islamic State-held Raqqa and Idlib, which is held by another rebel alliance. The Syrian government has faced increased military pressure since March, losing ground in the northwest, the south and the center of the country, where Islamic State seized the city of Palmyra from government control last month. Assad's control is now mainly confined to the major population centers of western Syria, where he has sought to shore up his grip with the help of Lebanon's Hezbollah Shi'ite militia, his main allies. An alliance of rebel groups known as "The Southern Front", which profess a secular vision for Syria, said its Deraa offensive had begun at dawn. The al Qaeda-linked Nusra Front also has a presence in the south. The violence briefly spilled over into Jordan where a stray mortar bomb killed a market vendor and wounded several others. "If the battle takes time, we are prepared. We have begun the preparatory shelling but we cannot assess the situation right now," said Issam al-Rayyes, spokesman for the Southern Front. Deraa's provincial governor Khaled al-Hanous told state TV the insurgents had launched "a real war with intensified shelling with various weapons or artillery on citizens in the neighborhoods of the city and on hospitals, schools and infrastructure". The rebels had not made "one meter of progress", he said.