Taoiseach Bertie Ahern said today he was "shocked and appalled" at the deaths of up to 50 Lebanese civilians in an Israeli air strike in the village of Qana.
In a statement, Mr Ahern said the incident "strongly underlines the clear message the Government has been giving out which is that an immediate ceasefire on all sides is urgently necessary.
Rescuers line up bodies outside the Tyre hospital after the Israeli air raid on Qana
"Military actions are only making a solution more difficult."
The Taoiseach said Minister for Foreign Affairs Dermot Ahern would be making Ireland's views known at a meeting of European Union foreign ministers in Brussels next Tuesday.
The Irish Anti-War Movement called the Qana strike a "war crime".
"The Irish government can no longer stand idly by," said spokesman Richard Boyd Barrett. "At the very least it must condemn this Israeli attrocity, demand an immediate ceasefire and expel the Israeli ambassador.
"The weaponry with which Israel is inflicting civilian carnage on Lebanon and Gaza is mostly supplied from the US. Apache helicopters and rockets have passed through Shannon en route to Israel from the US.
"As well as this US troops continue to use Shannon on their way to and from the occupation of Iraq in flagrant contravention of Irish neutrality," he said. "The supply of weapons to Israel through Shannon airport is no less than complicity in murder and war crimes."
Sinn Féin chief negotiator Martin McGuinness called on the White House and the British government to use their influence with the Israelis to secure an immediate ceasefire.
"The killing of 54 people in Lebanon this morning, including dozens of children marks a new low."