The Syrian army said on Sunday it had repulsed a major offensive by Islamic State militants in the northeastern city of Hasaka and driven out fighters who had taken over key installations on the southern edge of the city.
The northeastern corner of Syria is strategically important because it links areas controlled by Islamic State in Syria and Iraq. Syrian Kurds have also sought to expand their territorial control over a region stretching from Kobani to Qamishili they see as part of a future Kurdish state.
The militants, approaching from their stronghold the city of Shadadi, south of Hasaka city, made lightning advances this week after conducting around a dozen suicide attacks using explosives-laden trucks at army checkpoints in the city.
But Syrian state television, quoting an army source, said in a newsflash they had taken back an electricity station, a juvenile prison and two villages almost 2 km (1 mile) south of the city that had been occupied by militants.
The army announced later that the Syrian air force had bombed militant posts in a string of villages south of Hasaka, including Tel Fawaz, Mishrafa, Makhroum, Tel Baroud and Um Madfaa which it said had killed "tens of terrorists and destroyed their vehicles".
This week's attacks were the biggest push launched by the militants on Hasaka, the provincial capital of the oil and grain producing province of Syria, that is divided into zones run separately by the government of President Bashar al Assad and a Kurdish administration.
The offensive was meant to relieve pressure on hardline jihadists who have otherwise lost significant ground recently to Kurds and some local Arab tribes backing them after their loss of Arab-inhabited villages around Ras Al Ayn and Tal Abyad – both major towns north-west of Hasaka along the Turkish border.
Residents said Kurdish forces seized several Arab-inhabited villages west of Kurdish controlled Ras Al Ayn city, including al-Jasoum and Sawadieh, following the recent capture of the strategic Jabal Abdul Aziz mountain range..
The Kurds, whose well-organized militia YPG receives air support from a US led alliance bombing Islamic State, had been helping government forces to repel last week's attack, according to the Syrian Observatory for Human Rights.
The Observatory, which tracks violence across the country, said at least 71 army and loyalist militias were killed in the week-long battles with Islamic State.
The United States and its allies said on Thursday they staged 17 air strikes on Islamic State targets in Syria and Iraq with four of the raids near Hasaka.