Western and Arab foreign ministers were to meet in Paris on Thursday for talks on the Syria crisis, with France warning Russia that its refusal to attend was plunging it deeper into isolation.

"I regret that Russia continues to lock itself into a vision that isolates it more and more, not just from the Arab world but also from the international community," Foreign Minister Alain Juppe told journalists.

Some 1,500 refugees have headed back to neighboring Syria since a fragile U.N.-backed truce went into effect a week ago, according to official figures published on Thursday.

Currently, a total of 23,558 Syrians are taking refuge in Turkey, said the prime minister's disaster and emergency management center, which gives a regular update on the figures.

Syria on Thursday signed a preliminary accord outlining a protocol for a U.N. mission to monitor a fragile week-old ceasefire in the strife-torn country, the two sides announced.

Deputy Foreign Minister Faisal al-Meqdad signed the deal with a member of a U.N. advance team, the ministry said in a statement.

Syrian Ambassador to Lebanon Ali Abdul Karim Ali stressed on Thursday that President Bashar Assad is fully implementing reforms, saying it is necessary to confront any power that doesn’t want the regime to play its role.

“Most Syrians support the reforms and the dialogue that President Assad and the Syrian leadership called for,” Ali told reporters after holding a meeting with Free Patriotic Movement leader MP Michel Aoun in Rabieh.

The U.N. refugee agency UNHCR said on Thursday the number of registered Syrians who have fled the unrest in their country to neighboring Jordan reached around 12,500 this month.

"In Jordan, some 12,500 Syrians had registered with UNHCR as of mid-April 2012. This figure is expected to increase as UNHCR and partners expand their outreach efforts and level of assistance to Syrians," the agency said in a statement on its website.

China said Thursday it was considering sending observers to monitor a Syrian ceasefire that came into force last week but is under threat as violence escalates.

"China is earnestly looking into whether to send observers to Syria or not," foreign ministry spokesman Liu Weimin told reporters at a regular briefing.

Russia said on Thursday it was skipping a meeting of foreign ministers on Syria in Paris as they were only aimed at isolating the regime and would hurt the chances of direct peace talks.

"It seems that this meeting is not aimed at finding the grounds for dialogue within Syria, but quite the opposite," the Russian foreign ministry said in a statement.

Turkish officials on Thursday began searching a German-owned vessel suspected of carrying weapons to Syria, a diplomatic source told Agence France Presse.

French President Nicolas Sarkozy on Thursday accused Syria's Bashar Assad of seeking to "wipe Homs from the map", comparing his campaign to the Libyan regime's attacks on the city of Benghazi.

"Bashar Assad is lying in a shameful way, he wants to wipe Homs from the map like (former Libyan strongman Moammsr) Gadhafi wanted to wipe Benghazi from the map," Sarkozy told Europe 1 radio.

Syrian troops killed a civilian and three civilians were also wounded on Thursday a week into a U.N.-backed truce, a Britain-based human rights watchdog said.

Syrian security forces opened fire in the northeastern oil city of Deir al-Zour before clashes erupted between troops and rebel fighters, the Syrian Observatory for Human Rights said in a statement.