CAIRO/JERUSALEM, Aug 18 (Reuters) - Israeli and Palestinian officials said on Monday they have agreed to extend a Gaza ceasefire by another 24 hours to allow time for the sides to continue negotiations for terms of a possible agreement.

The deal was confirmed in Cairo and then Jerusalem minutes before a five-day ceasefire was due to expire. A Palestinian official close to the talks in Cairo said the extension would give both sides time "to complete the negotiations".

An Israeli official and security source said in Jerusalem that "on Egypt's request the ceasefire shall be extended by 24 hours to allow further negotiations."