Israel hit the Gaza Strip with more air strikes yesterday and warned its military action could last weeks, while its Islamist enemy Hamas vowed to keep up rocket attacks on Israeli cities.

Both sides rejected any notion of a ceasefire soon, three days after Israeli leaders launched bombing raids with the declared aim of halting rocket salvoes from the Hamas-controlled coastal enclave.

Defense Minister Ehud Barak said Israel, which is blockading Gaza, was gathering ground forces at the frontier and would expand its operation "as much as is necessary" to stop the rocket fire and "deal a heavy blow to Hamas".