As Islamist-led rebels continue to make further advances in Syria, India has advised its citizens to avoid travelling to the Arab republic and urged those staying in that country to exercise "utmost precaution" and restrict their movements.

In an advisory, the Ministry of External Affairs (MEA) asked the Indians living in the violence-hit country to leave by the earliest available commercial flights if they can.

The Islamist rebels had almost taken control of the central Syrian city of Homs on Thursday after capturing much of Aleppo, the country's largest city.

Tens of thousands of people have been fleeing Homs.

The MEA also urged the Indians residing in Syria to remain in touch with the Indian embassy in Damascus.

"In view of the situation prevailing in Syria, Indian nationals are advised to avoid all travel to Syria, until further notification," the MEA said.

"Indians currently in Syria are requested to remain in touch with the Indian embassy in Damascus at their emergency helpline number +963 993385973 (also on WhatsApp) and email ID hoc.Damascus@mea.Gov.In for updates," it said.

"Those who can, are advised to leave by the earliest available commercial flights and others are requested to observe utmost precaution about their safety and restrict their movements to the minimum," it added.

On Friday, India said it is closely following the unfolding situation in Syria.

"We have taken note of the recent escalation in fighting in the north of Syria. We are closely following the situation," MEA spokesperson Randhir Jaiswal said.

"There are about 90 Indian nationals in Syria, including 14 who are working in various UN organisations. Our mission remains in close contact with our nationals for their safety and security," he said.