BEIRUT: An al Qaeda affiliate based in Iraq and Syria has vowed to crush opposition groups it has been confronting in the worst outbreak of infighting among rebels since the start of the uprising against President Bashar al-Assad.
Heavy fighting between rebels in Syria has killed hundreds of people over the last five days and rattled the al Qaeda-linked faction, the Islamic State of Iraq and the Levant (ISIL).
The group lost its main base in the northern city of Aleppo to rival rebels on Wednesday, a monitoring group said.
The statement from the ISIL spokesman was issued late on Tuesday, hours after the head of the al Qaeda branch in Syria, the Nusra Front, called for a truce to halt the fighting.
The clashes have pitted many rebel groups in Syria, including Islamist forces, against ISIL and have been the bloodiest rebel-on-rebel violence since the civil war in Syria began in the first half of 2011.
"Crush them completely and kill the conspiracy in its cradle," said ISIL's spokesman, known as Abu Mohammed al-Adnani.
While both the Nusra Front and ISIL have roots in the global al Qaeda network and welcome foreign militants, the Nusra Front has focused its goals on toppling Assad instead of creating an Islamic state, which has been the main aim of ISIL.
Nusra forces have also cooperated more with other rebel groups and largely avoided the power struggles that ISIL has faced since wresting control of many opposition-held areas from other groups.
ISIL is the restructured al Qaeda branch of Iraq, but its spread into Syria is opposed by al Qaeda's central leadership, which has recognized the Nusra Front instead.
Adnani said fellow Islamists from the Sunni Muslim sect had been dragged into a conspiracy against it.
"Those who are from battalions raising the flags of Islam, who tricked you? Who implicated you and made you sign to fight against the mujahideen (holy warriors)?"