United Nations: The United Nations has urged restraint as Israel vowed to stop pro-Palestinian activists aboard an aid-laden flotilla from reaching the besieged, Hamas-ruled Gaza Strip.

"We understand from press reports that private citizens have assembled a number of ships carrying material intended for Gaza and will seek to deliver these materials directly by sea to Gaza," UN spokesman Martin Nesirky said in a statement.

"We strongly urge that all involved act with a sense of care and responsibility and work for a satisfactory resolution," he added.

Nesirky restated UN opposition "to the closure of Gaza and our concern at the insufficient flow of material through legitimate crossing points to meet basic needs, begin reconstruction, and revive economic life."

He said the world body continued to urge Israeli authorities "to facilitate a greater range and quantity of traffic through legitimate crossings to meet urgent needs in Gaza."

Israel has vowed to divert the ships to the southern Israeli port of Ashdod, where it will detain the activists before deporting them.

Israel and Egypt have sealed Gaza off to all but basic humanitarian aid since Hamas - which is blacklisted as a terrorist group by the European Union and the United States - seized power in June 2007.

Hamas on Thursday said Israel's threats to intercept the flotilla amounted to "Zionist piracy."