Security forces on Tuesday sealed entrances to Baghdad, set up checkpoints and searched cars during a protest to demand the approval of Iraq's state budget, an interior ministry official said.

The security measures were to "prevent the entrance of strangers and to control the security situation," the official said, adding there was a sit-in by supporters of powerful Shiite cleric Moqtada al-Sadr in Tahrir Square in central Baghdad calling for parliament to pass the budget.

The Syrian opposition should enter into talks with the regime of President Bashar Assad and put together a negotiating team, Russian Foreign Minister Sergei Lavrov said Tuesday after talks with U.S. Secretary of State John Kerry.

"We are counting on the opposition, who will be meeting with representatives of Western and a number of regional countries in Rome, to also declare itself in favor of dialogue because they have voiced contradictory statements on that account and not only declare but also name their negotiating team," Russian news agencies quoted Lavrov as saying in Berlin.

Delegates from 56 nations working on sanctions against Syria, agreed Tuesday in Sofia to ramp up political pressure against Bashar Assad's regime in what officials called their strongest declaration yet.

The "Friends of Syria" international working group on sanctions, which includes Western and Arab countries, called "on all members of the international community, especially members of the United Nations Security Council, to take swift, responsible and resolute action... with a view of depriving the regime of resources and instruments essential to its campaign of violence."

A record 150,000 people fled Syria this month to escape the worsening conflict now trapped in a "destructive military spiral," the top U.N. political official said Tuesday.

U.N. under secretary general Jeffrey Feltman also pointedly told the U.N. Security Council that abuses committed by President Bashar Assad's forces were "significantly" worse than those of the opposition, even though both could face war crimes charges.

The United Nations on Tuesday condemned the firing of a rocket from Gaza into Israel which it said had broken the longest ceasefire between the two sides in recent years.

Gaza militants fired the rocket in what they said was a response to the death of a Palestinian prisoner in an Israeli jail at the weekend. There are mounting international fears that serious new unrest could erupt in the Palestinian territories.

Egypt's main opposition coalition, the National Salvation Front, said Tuesday it will boycott upcoming parliamentary elections due to a lack of guarantees of a transparent process.

"The decision of the Front, unanimously, is to boycott the elections," NSF member Sameh Ashour told a news conference in Cairo after a meeting of the alliance grouping mainly liberals and leftists.

Radical Salafist Muslims murdered Tunisian opposition leader Chokri Belaid, with four suspects arrested and the killer identified but still on the run, Interior Minister Ali Larayedh said on Tuesday.

The breakthrough comes as Larayedh, named as prime minister-designate, presses efforts to form a new government aimed at pulling Tunisia out of a deep political crisis sparked by the February 6 killing of Belaid outside his home in Tunis.

Syrian rebels on Tuesday pushed into the outer perimeters of a police academy in the northern province of Aleppo after a fierce two-day siege in which more than 70 combatants were killed, a watchdog said.

Regime forces retaliated with air strikes on rebels around the school, located near the town of Khan Assal, but were unable to halt their advance, the Syrian Observatory for Human Rights said.

Saudi Arabia has been supplying Syrian rebels battling the regime of President Bashar Assad with arms bought from Croatia, according to The New York Times.

Citing unnamed U.S. and western officials, the newspaper reported late Monday that the Saudi-financed "large purchase of infantry weapons" was part of an "undeclared surplus" of arms left over from the Balkan wars in the 1990s and that they began reaching anti-regime fighters via Jordan in December.

Russian Foreign Minister Sergei Lavrov on Tuesday slammed "extremists" within the Syrian opposition who he said were blocking the start of dialogue in the war-torn country by making unrealistic demands.

Speaking hours before meeting new U.S. Secretary of State John Kerry for the first time in Berlin, Lavrov said that recent faint hopes that dialogue was possible between the opposition and the regime of Bashar Assad had dissipated.