At least 38 people, half of them civilians, were killed in violence across Syria on Thursday, monitors said, with fierce fighting between regime troops and insurgents in the rebel provinces of Idlib and Homs, as a spokesman for Kofi Annan said the U.N.-Arab League envoy expects both the Syrian government and the opposition to fully implement a ceasefire agreement by April 12.

The violence came despite the arrival in Damascus of a U.N. team dispatched by Annan to pave the way for a possible observer mission in Syria.

Syria's main opposition group on Thursday said a U.N. statement calling for all parties to end violence in Syria will simply give the regime more time to continue killing its own people.

"Such statements, issued amid continued killings, offer the regime the opportunity to push ahead with its repression in order to crush the revolt by the Syrian people," said Samir Nashar, member of the executive committee of the Syrian National Council.

U.N.-Arab League special envoy on Syria Kofi Annan is set to return to Damascus "very soon,” United Nations secretary-general Ban Ki-moon said Wednesday.

His announcement came a day after Western powers agreed to change a proposed U.N. Security Council statement on Syria after Russia refused to back any "ultimatum" to President Bashar Assad.

Syrian President Bashar Assad's forces are using "scorched earth methods" in cities across the country to crush a one-year-old revolt against his regime, Human Rights Watch charged on Thursday.

"City after city, town after town, Syria's security forces are using their scorched earth methods while the (U.N.) Security Council's hands remain tied by Russia and China," said HRW's Sarah Leah Whitson.

The newly-appointed President of the Special Tribunal for Lebanon Judge Sir David Baragwanath stated that the STL does not have jurisdiction in tackling the “so-called false witnesses file.”

He said in his first public statements since assuming his position: “We don’t have jurisdiction to tackle the false witnesses file until the Lebanese government, U.N., and Security Council agree to it.”

U.N. chief Ban Ki-moon expressed concern over the repercussions of the Syrian crisis on the implementation of Security Council resolution 1701 but hailed the Lebanese government’s efforts to ward off the impact of the upheaval in the neighboring country.

In his latest report on the implementation of resolution 1701, Ban said the Syrian regime’s crackdown on protestors has continued to affect Lebanon, and raised concerns that the unrest could have negative ramifications for the country’s stability.

Israel's Ambassador to the U.N., Ron Prosor, has warned the Security Council that Hizbullah’s alleged powerbase in western Africa is growing, the Israeli Ynetnews website reported Wednesday.

"Israel is particularly concerned over Hizbullah's use of the area as a base of terror operations,” the site quoted Prosor as saying. “Criminal initiatives bolster Hizbullah's efforts to create sleeper-cells in the area.”

Russia Wednesday welcomed Syrian President Bashar Assad's decree calling for a referendum on a new constitution ending single-party rule for the violence-wracked country.

"We certainly believe a new constitution to end one-party rule in Syria is a step forward. It is a welcome idea and we hope the constitution will be adopted," Russian Foreign Minister Sergei Lavrov said in The Hague.

The United Nations should consider setting up "humanitarian corridors" to get aid to Syrians caught in the brutal crackdown on pro-democracy protests, French Foreign Minister Alain Juppe said Wednesday.

"The idea of humanitarian corridors to allow NGOs (non-governmental organizations) to reach zones where there are absolutely scandalous massacres should be discussed at the Security Council," he told France Info radio.

Arab and western states are to launch a new bid at the United Nations this week to put pressure on Syria's President Bashar Assad, setting off new diplomatic hostilities between Assad's friends and foes.

Saudi Arabia and Qatar have drawn up a resolution backing an Arab League plan to end the 11-month-old crackdown on protests which could be voted in the U.N. General Assembly this week.