Jihadist militants captured at least 32 Syrian government soldiers and allied fighters in northern province of Aleppo, a monitoring group reported Thursday.

An array of rebel groups, including the al-Qaida-linked Nusra Front, also killed six government troops or allied militiamen others in intense battles on Wednesday in the town of Ritan in the northern countryside of Aleppo, where the Syrian army has recently waged a major offensive to dislodge rebels from key areas and cut their supply routes from neighboring Turkey.

The Syrian Observatory for Human Rights, a London-based monitoring group, said the jihadist groups captured the Syrian soldiers while they were attempting to flee their positions in northern Aleppo.

It said intense clashes continued Thursday near the towns of Hardtinin and Bashkoi.

Also on Thursday, video footage was posted online by jihadist groups purporting to show the captured soldiers hustled by rebels at night to an unknown destination. Some of the soldiers appeared wounded or limping.

The Observatory said at least 90 Syrian soldiers and allied fighters have been killed in battles in northern Aleppo since Tuesday, adding that 56 rebels were also killed in the same area.

It said the rebels managed to retake some towns fallen recently to the army.

The pan-Arab al-Mayadeen TV said a day earlier that hundreds of militants crossed from Turkey on Wednesday to join the rebels to fend off Syrian troops' advance.

Analysts believe that the broad offensive by Syrian army aims to dislodge rebels from key areas and besieging them in the eastern part of Aleppo, ahead of the possible implementation of a proposed "fighting freeze" plan.

The battles in Aleppo comes when the United Nations envoy to Syria, Staffan de Mistura, announced that the Syrian government has accepted his proposal to freeze fighting in the city as a prelude to further pacification.

On Tuesday, de Mistura said the Syrian government had indicated "its willingness to halt... all sorts and all types of aerial bombing and artillery shelling for a period of six weeks all over the city of Aleppo" from a date to be announced by Damascus.

The prospects of success for the freeze plan appear slim as a number of rebel factions, mainly al-Qaida-linked ones, reject it.