Syria announced Wednesday it would cease all operations and attacks against opposition forces on Thursday, adding, however, that it would remain "on alert" should armed groups attack civilians.

The statement by the Syrian Defense Ministry came hours before a planned deadline that is part of the UN-sponsored peace plan, and after which both Syrian forces and opposition groups must hold their fire.

"After our armed forces carried out successful missions in combating the criminal acts of terrorist groups and imposed the authority of the state on its land, (it has been) decided to end operations starting tomorrow morning," a TV newsflash said.

"Our armed forces remain on alert to confront any assault by armed groups against civilians and the security and armed forces," it said.

Speaking in Iran, where he is visiting as part of the attempt to safeguard the peace deal, special UN and Arab League envoy to Syria Kofi Annan said that he had received a written statement from Damascus, according to which Syrian forces would cease fire on 6 A.M. Thursday.

In a joint press conference with Iranian Foreign Minister Ali Akbar Salehi, Annan also warned against arming Syrian opposition groups, adding that such a move could devastate the region.

Also speaking at the press conference, Salehi said Syria's government must be allowed enough time to implement Annan's peace plan

"We believe that the people of Syria, like other countries, have the right to enjoy all the rights enjoyed by any other country, such as freedom of political parties, such as freedom [to hold] elections, such as a constitution that encompasses all the desires and aspirations of a nation. These are the points we have mentioned," he added.

However, Salehi added, "if any change is to occur in Syria, that change should be implemented by the Syrian government itself. And the Syrian government, led by Mr. Bashar Assad, has promised to implement all these changes and to fulfill the demands of the people," saying that "enough time should be given to the Syrian government.”

"We have a slight disagreement on this point with certain other countries in the region and the West. They think in a different way. They want to see changes taking place there in a different way," the top Iranian official said.

Slaehi lauded Annan's peace plan for making "no mention of the removal of the head of the government in Syria, but rather what has been stated is that the sides sit down and negotiate and that enough time should be given to implement the changes."

However, despite Syria's proclaimed intention to hold its fire on Thursday, Assad's forces were bombarding targets in Hama and Daraa, with troops raiding the Sisa neighborhood of central Damascus where many of the foreign embassies are located.