The al-Qaeda-linked Islamist State of Iraq and the Levant executed dozens of rival fighters over the last two days as the group recaptured most territory it had lost in the northeastern Syrian province of Raqqa, activists said.One of the activists, who spoke from the province on condition of anonymity, said up to 100 fighters from the Jabhat al-Nusra, another al-Qaeda affiliate, and the Ahrar al-Sham brigade, captured by ISIL in the town of Tel Abyad on the border with Turkey, the nearby area of Qantari and the provincial capital city of Raqqa, were shot dead.There was no independent confirmation of the report."About 70 bodies, most shot in the head, were collected and sent to the Raqqa National hospital,” the activist said."Many of those executed had been wounded in the fighting. The fact that Jabhat al-Nusra and Ahrar al-Sham are ideologically similar to the ISIL did not matter,” he added.ISIL’s growth has alarmed Western nations, who are pushing the opposition to attend peace talks in Switzerland in 10 days’ time, and has helped President Bashar al-Assad to portray himself as the only secular alternative to extremism. Fighting between ISIL, rival fighters and more moderate rebels has killed hundreds of people over the last 10 days and shaken the group led by foreign jihadists.But ISIL regrouped and recaptured much of its stronghold in Raqqa city on Sunday, activists said, dealing a blow to rival rebel groups backed by Gulf Arab and Western states.Among those reportedly executed on the weekend was Abu Saad al-Hadram, Jabhat al-Nusra’s commander for Raqqa province who was captured several months ago as tension mounted between the foreign-led ISIL and the more home-grown al-Nusra, opposition sources said. AgenciesIn Raqqa, the only provincial capital under rebel control, activists said ISIL fighters battled remnants of rival fighting units, including the Jabhat al-Nusra in several neighbourhoods.