An Israeli air strike on the southern Lebanese town of Qana, killing more than 50 people including many children, has been denounced by the Lebanese prime minister as a "war crime".
Mr Siniora called for an immediate ceasefire
Below is a selection of quotes on the latest incident.
LEBANESE PRIME MINISTER FOUAD SINIORA
Out of respect for the souls of our innocent martyrs and the remains of our children buried under the rubble of Qana, we scream out to our fellow Lebanese and to other Arab brothers and to the whole world to stand united in the face of the Israeli war criminals.
The persistence of Israel in its heinous crimes against our civilians will not break the will of the Lebanese people. There is no place on this sad morning for any discussion other than an immediate and unconditional ceasefire as well as the international investigation into the Israeli massacres in Lebanon now.
ISRAELI PRIME MINISTER EHUD OLMERT
All the residents were warned and called upon to leave. There are hiding places for rockets inside the village and the village itself is a safe haven for those who launch rockets. We have no policy to target innocent civilians.
I think it needs to be clear that Israel is in no rush to reach a ceasefire before we get to a point where we could say that we have achieved the main objectives we had set forth.
This requires a ripening of the diplomatic process and a specific agreement regarding the formation of the force that will operate from the areas from which Israel was threatened in this period.
This horrific massacre will not go without a response.
US PRESIDENT GEORGE W BUSH
The United States is resolved to work with members of the United Nations Security Council to develop a resolution that will enable the region to have a sustainable peace, a peace that lasts, a peace that will enable mothers and fathers to raise their children in a hopeful world. May God bless those who lost their lives
UK PRIME MINISTER TONY BLAIR AND GERMAN CHANCELLOR ANGELA MERKEL
The tragic events of today have underlined the urgency of the need for a ceasefire as soon as possible.
It is now necessary to work in New York on the pre conditions for such a ceasefire, which is a political agreement on the full implementation of resolution 1559.
UN SECRETARY GENERAL KOFI ANNAN
The most urgent need is to bring the fighting to a halt without further delay. For that, this [Security] Council has a solemn responsibility.
Action is needed now - before many more children, women and men become casualties in a conflict over which they have no control.
EU FOREIGN POLICY CHIEF JAVIER SOLANA
I have talked to the prime minister of Lebanon... I have expressed to him my profound dismay and deep sorrow at the attack and the death of innocent civilians in Qana. Nothing can justify that.
I have transmitted to him that the European Union is continuously working to reach an immediate ceasefire.
FRENCH PRESIDENT JACQUES CHIRAC
France condemns this unjustified action which demonstrates more than ever the need for an immediate ceasefire without which there will only be other such incidents.
CHINESE FOREIGN MINISTRY SPOKESMAN LIU JIANCHAO
China strongly urges the two sides involved in the conflict to cease fire immediately to avoid further disaster.
The Lebanon-Israel conflict has caused grave humanitarian damage.
SWEDISH FOREIGN MINISTER JAN ELIASSON
It is time to end this madness. The UN Security Council must accept its responsibility and immediately adopt a resolution to bring an end to hostilities.
SPANISH FOREIGN MINISTRY
The Spanish government repeats it call for an immediate ceasefire that would end the violence and spare us from having to lament tragedies like this one in the future.
POPE BENEDICT XVI
In the name of God, I call on all those responsible for this spiral of violence so that weapons are immediately laid down on all sides.
ARAB LEAGUE SECRETARY GENERAL AMR MOUSSA
The attacks that Israeli forces are launching targeting civilians and the Lebanese infrastructure are another confirmation of Israeli aggressive intentions.
PALESTINIAN PRIME MINISTER ISMAIL HANIYA
We believe that this barbarism, repression, and these massacres which are being committed cannot achieve their goals and cannot break the Palestinian and Lebanese peoples' will of steadfastness, nor can plans aimed at liquidating the Palestinian cause or terminating the nation's points of resistance be implemented.
Hence, we call on the Arab League, the Organisation of Islamic Conference, and the international community to quickly and responsibly act in favour of halting these massacres in Palestine and Lebanon and to curb the Israeli aggression against the Palestinian and Lebanese land.
EGYPTIAN PRESIDENT HOSNI MUBARAK
The Arab Republic of Egypt expresses its profound alarm and
its condemnation of the irresponsible Israeli bombing of the
Lebanese village of Qana, which resulted in innocent casualties,
mostly women and children.
JORDAN'S KING ABDULLAH
This criminal aggression is an ugly crime that has been committed by the Israeli forces in the city of Qana that is a gross violation of all international statutes.
SYRIAN PRESIDENT BASHAR AL-ASSAD
The massacre committed by Israel in Qana this morning shows the barbarity of this aggressive entity. It constitutes state terrorism committed in front of the eyes and ears of the world.
IRANIAN FOREIGN MINISTRY SPOKESMAN HAMID REZA ASEFI
The Qana bombing is the outcome of [US Secretary State Condoleezza] Rice's trip to the region. Some American officials should be put on trial for the crimes in Lebanon.
IRAQI GRAND AYATOLLAH ALI AL-SISTANI
Islamic nations will not forgive the entities that hinder a ceasefire.
it is not possible to stand helpless in front of this Israeli aggression on Lebanon.
If an immediate ceasefire in this Israeli aggression is not imposed, dire consequences will befall the region.