Israeli tank shelling and airstrikes killed 24 Palestinians including seven children in Gaza on Wednesday, health officials said, the latest violence to undermine the nearly four-month-old ceasefire in the enclave.

Among the dead was a medic who rushed to help victims of a strike in the southern city of Khan Younis and was then killed by a second attack on the same location, health officials said.

Other strikes hit Gaza City ?in the north, where health officials said a 5-month-old boy was killed. The attacks come three days after Israel reopened Gaza¡¯s main border crossing with Egypt, ?a big ?step envisaged by the U.S.-backed truce deal.