The U.N. on Tuesday decried numerous executions of civilians in Iraq by the Islamic State group, warning that educated women appeared to be especially at risk.

The jihadist group is showing a "monstrous disregard for human life" in the areas it controls in Iraq, the U.N. human rights office said.

A U.N. official said on Tuesday that the flow of Syrian refugees into Lebanon has dropped sharply due to restrictions recently imposed by Lebanese authorities.

Although Lebanese border officials began informally restricting the entry of Syrians last October, the country officially imposed visa regulations earlier this month on their neighbors. The move was the first such in decades.

Israel is on high alert for possible attacks from Hizbullah following an airstrike on its members in Syria, Israeli defense officials said Tuesday, as the Jewish State boosted deployment of its "Iron Dome" anti-missile aerial defense system along its northern frontier.

Israel has also increased surveillance activities in the area which borders Lebanon and Syria, the officials said.

The army command denied on Tuesday that Military chief General Jean Qahwaji made a statement to the pan-Arab daily Asharq al-Awsat concerning the Israeli strike that killed a prominent Hizbullah fighter with five other members in Syria's Golan Heights.

“The army command completely denies that Qahwaji made any remarks to the newspaper or any other media outlet concerning the strike,” it said in statement.

German police searched more than a dozen suspected Islamist sites early on Tuesday, seeking associates of two men who have been detained for allegedly planning an attack in Syria, police said.

No one was detained in the raids, which saw more than 200 officers search 13 apartments in Berlin, a neighboring region and in the east, said a police statement.

The Islamic State group threatened in a video Tuesday to kill two Japanese hostages within 72 hours unless it receives a $200 million ransom, but Tokyo vowed it would not bow to "terrorism".

Japanese Prime Minister Shinzo Abe, in Jerusalem on the latest leg of a Middle East tour, demanded the jihadists immediately free the two hostages unharmed.

Hizbullah leader Sayyed Hassan Nasrallah is expected to give a speech on Sunday following the death of six party members in an Israeli strike in Syria as the movement investigated whether the attack was a result of a major security breach.

As Safir daily said Tuesday that Nasrallah had been scheduled to address his supporters on the seventh assassination anniversary of military commander Imad Mughniyeh on February 16.

Progressive Socialist Party leader MP Walid Jumblat stressed on Tuesday that Lebanon cannot endure any “adventure,” pointing out that the Israeli airstrike that killed a prominent Hizbullah fighter with five other members occurred in Syria's Golan Heights and not on Lebanese territories.

“We are only concerned with the occupied land on Kfarshouba Hills and the Shebaa Farms and have nothing to do with what happens in Syria,” Jumblat said in comments published in al-Mustaqbal newspaper.

U.S. Senator John McCain on Monday urged the deployment of international ground forces to combat jihadists in Syria and Iraq, as he toured the Middle East with a Senate delegation.

"For months we've been bombing (Syrian border town) Kobane and we still haven't driven ISIS out," the Senate Armed Services Committee chairman told reporters in Jerusalem, using an acronym for the Islamic State group.

Syria has begun destroying its remaining chemical weapons production sites, despite being hampered by bad weather and logistical problems, the world's chemical watchdog said Monday.

"Destruction operations commenced in December," Organization for the Prohibition of Chemical Weapons (OPCW) spokesman Peter Sawczak told Agence France-Presse in The Hague, without elaborating.