Syrian authorities on Thursday sent text messages over cell phones nationwide with a message for rebels fighting President Bashar Assad's regime: "Game over."

The messages signed by the Syrian Arab Army also urged the rebels to surrender their weapons and warned the countdown to evict foreign fighters has begun. The texts appear to be part of the regime's psychological battle against the rebels, but are highly unlikely to have any effect on fighters intent on toppling Assad.

Russia's U.N. Security Council veto is "just an excuse" for world powers not to intervene in Syria, but the regime is going to fall without their help, the chief of Syria's Muslim Brotherhood told AFP Thursday.

"Russia is just an excuse for the rest of the great powers not to topple (Syrian President Bashar Assad's) regime," said Mohammed Riyad al-Shaqfa, complaining of an international unwillingness to "get sucked into" the conflict in Syria.

United Nations Special Coordinator for Lebanon Derek Plumbly visited on Thursday the Bekaa Valley to examine the situation along Lebanon’s borders with Syria and the conditions of displaced Syrians in that area, announced his press office in a statement.

“I have been impressed by what I have seen of the dedication of the Lebanese army in the border areas but remain seriously concerned by the impact of cross-border fighting and incursions, from whatever source,” said Plumbly.

Progressive Socialist Party leader MP Walid Jumblat highlighted on Thursday the attack on the Syrian army headquarters on Wednesday, saying that the army today is “burning and being burnt due to the ruling regime and its lies.”

He said in a statement: “The burning of the headquarters means that Syria will sink into chaos, civil war, and destruction along with the Syrian army.”

Russian President Vladimir Putin on Thursday accused the West of pursuing policies that had destabilized states in the Arab world and now risked creating chaos in Syria.

"The most important thing is that our partners cannot stop themselves," news agencies quoted Putin as saying at his local Moscow residence at a meeting with local residents of the Ryazan region in central Russia.

Unidentified attackers blew up an oil pipeline in the northeast Syrian province of Hasaka on Thursday, after a car bomb attack on an army checkpoint near Aleppo overnight, a watchdog said.

The latest violence came after more than 300 people were killed nationwide on Wednesday in what the Syrian Observatory for Human Rights said was the bloodiest day of the 18-month conflict so far.

Military prosecutors have charged eight Syrians with "unlawful assembly" after riots erupted this week at their refugee camp in northern Jordan, a judicial official said on Thursday.

"State security court prosecutors on Wednesday accused eight Syrian refugees of unlawful assembly and carrying out riots" at the U.N.-run Zaatari refugee camp near the border with Syria, the official told Agence France Presse on condition of anonymity.

The U.N. refugee agency warned Thursday there could be as many as 700,000 Syrian refugees in countries neighboring the war-torn nation by the end of the year, up from 300,000 now.

"There may be up to 700,000 Syrian refugees in neighboring countries by the end of the year," Panos Moumtzsis, the UNHCR's chief coordinator for Syrian refugees, told reporters in Geneva.

A rocket and mortar rounds fired from Syria that hit the Israeli-occupied Golan Heights in recent days were not aimed at the Jewish state, an Israeli minister said on Thursday.

"The fire was the result of inter-Syrian fighting and we have no intention of getting involved in that issue," Regional Development Minister Silvan Shalom told Israeli public radio.

A Syrian unit infiltrated on Thursday the Bekaa region of al-Qaa where it destroyed the house of Mohammed Aqil al-Radi, reported the National News Agency.

Future television meanwhile said that a shell fired from the Syrian side of the border landed on Abu Talal al-Radi's house in al-Qaa.