By Nidal al-Mughrabi and Ibraheem Abu Mustafa DOHA/GAZA (Reuters) -Medical facilities are at risk of collapse in Khan Younis, the southern Gaza city now at the focus of Israel’s offensive, the Gaza Health Ministry warned on Sunday, as fighting raged across the Palestinian enclave. Residents said Israeli planes and tanks also pounded areas in Gaza City to the north, where Israel has been pulling out troops. The fighting could be heard in the nearby towns of Beit Lahiya and Jabalia, near to Gaza City. Israel’s military said it was engaged in “intensive battles” in Khan Younis, where it said troo…