A ceasefire took effect Tuesday in conflict-ravaged Yemen as warring sides began UN-brokered peace talks in Switzerland, according to the United Nations and the Saudi-led coalition battling Iran-backed rebels, AFP reports.

Limited violations of the truce were reported shortly after it began at midday (0900 GMT), with several mortar rounds hitting government forces in the southwestern province of Taez, according to a Yemeni security official.

The Saudi-led coalition, which launched an air war against the Huthi Shiite rebels and their allies in March, said the ceasefire had started as scheduled following a request by Yemeni President Abedrabbo Mansour Hadi.

The  ceasefire was postponed because of a deadly attack by Houthi rebels on the Saudi Arabia-led coalition forces and killing two Arab commanders.

It will coincide with the United Nations brokered peace talks in Switzerland.

The civil war in Yemen which began in March has been going on for more than nine months.

Following a request by Yemeni President Abd-Rabbu Mansour Hadi, the ceasefire will now begin at 12 pm local time, the Saudi led coalition said, Aljazeera reported.

Yemeni government delegates along with representatives of the Shia Houthi rebel group are expected to attend the UN-backed negotiations in Switzerland, BBC said.

On Monday, a Saudi Colonel and an Emirati officer were killed near the city of Taiz, southwest of Yemen. "They were carrying out their duties supervising operations to liberate Taiz," a Saudi Press news agency said.

The attack came as a big blow to the Saudi-led coalition and almost jeopardised the moves for the proposed 7-day ceasefire.

So far, approximately 6,000 people have been killed in the conflict, most of them civilians, according to a BBC report.

"The ceasefire will last for a period of seven days starting from 15-21 December in conjunction with the launch of consultations, and will be renewed automatically in the event of the commitment of the other party," a statement released by the Saudi Press news agency stated.

The Houthi rebel-controlled media confirmed the deaths and said they were killed in a rocket attack on the Red Sea coast, Aljazeera reported.

The Saudi-led coalition was cobbled together in March after Houthi rebels captured Sanaa and advanced to the city of Aden. Since then, coalition and pro-government forces have recaptured the city of Aden and Sanaa but haven't been able to drive out the rebels from Taiz.

In Yemen, the humanitarian situation is constantly declining. More than 21 million people are in need of aid, the BBC report stated.

So far, more than a 100 troops including soldiers from the UAE, Bahrain, and Qatar have been killed  due to the Yemen conflict, according to the Aljazeera report.