BEIRUT (Reuters) - The Syrian army and allied forces captured the last major town held by Islamic State in Aleppo province on Sunday, state media and a war monitoring group said.

State-run news agency SANA said army units made strategic gains in the rural east of the province.

The Syrian Observatory for Human Rights, a Britain-based war monitoring group, said government forces entered the town of Maskaneh after weeks of heavy fighting.

The advance brings Russian-backed government forces to the border of Raqqa province, which is largely under the control of U.S.-backed militias also fighting Islamic State.

A Syrian military source said the army “restored security and stability” to Maskaneh and nearby positions. Troops also regained large generators that power a main water pumping station, the source said. The army had retaken the water plant from Islamic State in March.

Islamic State militants have been holed up in desert areas in the southeast corner of Aleppo, now their only presence in the province. Syrian government forces control Aleppo city and much of the province’s east, while rebel groups hold swathes of its west.

The town of Maskaneh lies on the western banks of the Euphrates river in Aleppo province, some 10 kilometers from the provincial border with Raqqa. The next major urban center across the border to the east is Tabqa, which the U.S.-backed Syrian Democratic Forces captured from Islamic State in May.

The United States has so far ruled out cooperating with the government in the fight against Islamic State in Syria, where separate military campaigns have forced the jihadist group into retreat.

Islamic State militants still control tracts of Syria’s eastern deserts and most of Deir al-Zor province bordering Iraq, but they have been on the back foot over the past year.

With the help of Russian air power and Iranian-backed militias, the Syrian army has been stepping up attacks on Islamic State in the eastern Aleppo countryside.

The Syrian army said on Saturday that it seized mountainous territory from Islamic State east of the road that links Damascus to Aleppo, a critical lifeline for the government that has often come under IS attack. [nL8N1J0089]