An explosion from an Israeli airstrike is seen in Rafah, in the southern Gaza Strip, 13 Jan 2009

Israel says it has inflicted serious damage on Hamas' military infrastructure but it says much more work remains to be done before it stops its offensive in Gaza. There are no signs of a let-up in the conflict, despite diplomatic efforts.

Gunfire rings in the Gaza Strip for yet another day.

Residents inside the enclave say the pre-dawn hours of Tuesday saw some of the most intense fighting since the start of the Israeli offensive 18 days ago. Israeli ground troops pushed deeper into Gaza City, pounding targets with artillery and tank fire, and what Israeli officials say were 60 air strikes between Monday and Tuesday.

Israel Defense Forces Chief of Staff Gabi Ashkenazi says Israeli forces have hit Hamas hard, but he says the offensive will continue until Israel's goals are achieved.

Ashkenazi says Israeli forces have inflicted damage on Hamas including its infrastructure, its government institutions and its military wing. But he says there is still much work ahead. He says his forces are working to inflict further damage on the military infrastructure and to limit the rocket fire into Israel.

The Israeli aim is to end Hamas' ability to fire rockets at its civilians in southern Israel. Tuesday, militants fired more rockets shortly after sunrise.

Both sides say they are willing to consider a cease-fire, but not until their goals are achieved.

Ismail Haniyeh  (File photo)

Hamas' leader in Gaza, Ismail Haniyeh, appeared on television from a hideout on Monday. He said victory is at hand for Hamas, but said he is ready to negotiate a cease-fire if Israeli forces pull out of Gaza and end a blockade of its borders.

Haniyeh says Hamas officials are working in diplomatic channels and are receptive toward any initiative to stop the aggression against the people in Gaza. He also says the Israeli forces should be removed immediately from Gaza and he says the border crossings should be re-opened.

Palestinian medical officials say the casualties have now surpassed 900, and the humanitarian situation continues to worsen. The head of the international Red Cross entered Gaza on Tuesday. At least 13 Israelis have died in the fighting.

U.N. Secretary-General Ban Ki Moon is due in the region on Wednesday, to give cease-fire efforts yet another push.