Hamas has officially told Egypt that it rejects an Egyptian-proposed Gaza ceasefire, a spokesman for the Palestinian group said on Wednesday.

"The outcome of discussions within the internal institutions of the movement was to reject the proposal and therefore, Hamas informed Egypt last night it apologises for not accepting it," spokesman Sami Abu Zuhri said.

Hamas's armed wing, Qassam Brigades, had already spurned the Egyptian plan on Tuesday, and Israel, which briefly halted its Gaza offensive, resumed attacks Tuesday afternoon.