A previously unknown armed group calling itself the "Syrian Revolutionaries - Aleppo Province" claims to have kidnapped a group of Lebanese Shia pilgrims in exchange for an apology from Hezbollah leader Hassan Nasrallah.

"The kidnapped Lebanese are being looked after by us and are in good health," the group said in a statement received by Al Jazeera.

"Negotiations for their release are possible as soon as Nasrallah apologises ... Our problem is not with any particular community but with those who assist in the suppression of the uprising."

Hezbollah, the leading force in the current ruling coalition in Beirut, has close relations with the regime of Syrian President Bashar al-Assad and Iran.

Since the dozen or so returning pilgrims went missing on May 22 on their way back from Iran, Nasrallah has called for restraint and urged his followers to refrain from sectarian revenge attacks against Syrian Sunnis.

On Sunday, the outgoing head of the opposition Syrian National Council, Burhan Ghalioun, said the pilgrims were still being held in Syria. Earlier reports said they had resurfaced in Turkey.

"We spoke with some parties who had contacts with the group and we offered our assistance to have them freed," Ghalioun said.

The rebel Free Syrian Army, a loose coalition of armed groups that communicate with the SNC, has denied any involvement in the kidnapping.