ISIL capital: Syrian army 'crosses into Raqqa province'

The Syrian army has crossed the boundary of Raqqa province after advancing in a major Russian-backed offensive against the Islamic State of Iraq and the Levant (ISIL) group, according to the Syrian Observatory for Human Rights (SOHR).

Heavy Russian air strikes hit ISIL-held territory in eastern areas of Hama province, near the boundary of Raqqa, on Friday to facilitate the Syrian army's advance, the UK-based SOHR said on Saturday.

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"Regime troops backed by Russian air strikes and Russian-trained militia entered Raqqa province on Saturday morning," Rami Abdel Rahman, SOHR's director, told the AFP news agency.

SOHR said at least 26 ISIL fighters and nine Syrian government and allied troops were killed in the fighting. 

It was the first time that government troops had entered Raqqa province since they were ousted by ISIL fighters in August 2014.

Raqqa city, further east, is ISIL's de facto capital in Syria and, along with Mosul in Iraq, the ultimate target of the anti-ISIL coalition seeking to destroy the group's self-declared caliphate.

The Syrian army was making its advances f-rom the Athriya area of eastern Hama province, close to the provincial border with Raqqa.

The Tabqa dam on the Euphrates River, 40km upstream f-rom Raqqa city, is also the target of a separate offensive launched by US-backed Kurdish-led forces advancing f-rom the north late last month.

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Al Jazeera's Hashem Ahelbarra, reporting f-rom Gaziantep, on the Turkish side of the Turkey-Syria border, said the push into Raqqa f-rom was a "significant development" but there was a still "a long way to go" before the Syrian army reached Taqba, whe-re ISIL fighters have a strong presence.

"Raqqa is besieged by government troops f-rom the west and Syrian factions f-rom the north and f-rom the east - the south is linked to the bordering province of Deir Az Zor which is still an ISIL stronghold," Ahelbarra said.

"Now, whoever controls Raqqa will face a mammoth challenge, which is basically securing a vast territory," he added, noting that both the Syrian government and the Kurdish factions cannot maintain a significant presence of troops in the province as they are also involved in heavy fighting in different battlefields elsewhe-re in Syri