CAIRO, Oct 9 (Reuters) - An Israeli airstrike on a school sheltering displaced people in central Gaza killed at least 28 people, including women and children, on Thursday, while three hospitals in the north were told to evacuate putting patients' lives at risk, medics say.

The strike, in which many more were wounded, happened in the city of Deir Al-Balah, where a million people have taken shelter after fleeing fighting elsewhere after more than a year of war.

The Israeli military said on Thursday it had carried out a "precise strike on terrorists", who had a command and control centre embedded in a school.

"This is a further example of the Hamas terrorist organization’s systematic abuse of civilian infrastructure in violation of international law," the military statement said.

Hamas denies such allegations. Medics said 54 other people were wounded at the school.

In the north of the enclave, the Israeli military is pushing on with an offensive begun six days ago, when it sent its troops into Jabalia, the largest of Gaza's eight historic refugee camps and the nearby towns of Beit Hanoun and Beit Lahiya.

Palestinian health officials say at least 130 people have been killed so far in the operation, which Israel says is aimed at preventing Hamas from regrouping.

The military has told residents to evacuate an area in which the U.N. estimates more than 400,000 people are trapped.

The health officials said the Israeli military on Wednesday gave patients and medics 24-hours to leave the Indonesian, Al-Awda and Kamal Adwan hospitals or risk being stormed as happened earlier in the war at the Al Shifa Hospital in Gaza City.

Israel, which has not yet commented on evacuation orders for medical facilities, has said Hamas has command facilities embedded in the hospitals, which it denies.