GENEVA - An advance team of UN ceasefire monitors started work in Syria on Monday, seeking to ensure that both government forces and the opposition respect the terms of a truce, mediator Kofi Annan's spokesman said.

A team of UN monitors walk through a hotel in Damascus April 16, 2012. [Photo/Agencies]

A team of six observers arrived in Damascus late on Sunday night, led by Moroccan Colonel Ahmed Himmiche.

"The mission will start with setting up operating headquarters this morning, and reaching out to the Syrian government and the opposition forces so that both sides fully understand the role of the UN observers," spokesman Fawzi Ahmad said in a statement.

"The remaining 25 are expected to arrive in the next few days," he said.

The United Nations Security Council agreed on Saturday to send the unarmed monitors to supervise the ceasefire that officially began last Thursday.

On Sunday, Fawzi said he expected the Security Council to adopt a second resolution by the end of the week to authorise the deployment of a full observer mission of at least 250 monitors, including human rights experts.