The UN military observers killed in yesterday's Israeli air strike in Lebanon were from Austria, Canada, China and Finland.
The four men, who were attached to UNIFIL, died when an Israeli bomb destroyed their observation post near Khiam.
The Chinese Foreign Ministry in Beijing has summoned the Israeli ambassador to demand an apology.
The UN has said the air strike came after the shelter had been shelled 14 times by Israeli artillery in spite of repeated pleas from the UN commander on the ground.
It is understood there had been a number of near misses earlier in the day and that UNIFIL personnel had contacted Israeli officers about the situation.
A UN rescue team also came under fire as it searched the rubble.
An Israeli government spokesman, Mark Regev, has denied suggestions by the UN Secretary-General, Kofi Annan, and the Minister for Foreign Affairs, Dermot Ahern, that the observers might have been singled out.
He said Israel does not target UN personnel and, since the beginning of the current conflict, it has made a consistent effort to ensure the safety of all members of UNIFIL.
Israel's Prime Minister earlier expressed his 'deep sorrow' at the deaths. Ehud Olmert spoke to Mr Annan this morning.
Mr Annan said he was shocked by what he called the apparent deliberate targeting of the UNIFIL position. He called for an immediate investigation by the Israelis.
It is understood there were at least 14 UN staff inside the post at Khiam in southern Lebanon when it was destroyed.
Eight Israeli soldiers killed in Bint Jbeil
It has been confirmed that eight Israeli soldiers were killed today in clashes with Hezbollah in the border town of Bint Jbeil in southern Lebanon.
Israeli ground forces have been meeting stiff resistance from Hezbollah fighters around Bint Jbeil over the past several days.
Hezbollah leader Hassan Nasrallah had insisted in a television broadcast earlier that the town was not in Israeli hands.
Two Israeli soldiers were killed in pitched battles with Shia militiamen near Bint Jbeil on Monday as Israeli forces moved deeper into Lebanon.
14 other soldiers were injured, six reportedly hit by friendly fire.
And at least six people were injured, one seriously, in rocket attacks on Israel's main industrial city, Haifa.
A taxi driver was seriously injured when a rocket hit a Haifa suburb and five more were injured by a rocket that fell in the city centre.
No agreement at UN conference
A conference of foreign ministers in Rome on the violence in the Middle East has failed to reach agreement on a call for an immediate ceasefire.
In a statement after the meeting the 15 nations present vowed to work with 'utmost urgency' for a truce.
The meeting, which was called by the US Secretary of State Condoleezza Rice, brought together EU and Arab nations plus the US and Russia, but not Israel, Iran or Syria.
