The Israeli military said it would open another evacuation route on Wednesday for people fleeing Gaza City as international alarm grew over the hundreds of thousands of Palestinians still sheltering there amid Israel’s heavy bombardment and widening ground assault. Before the expanded offensive was announced on Tuesday, the military ordered people in Gaza City to go to what it described as a humanitarian zone in the south. The Israeli military said that more than 350,000 people had fled the northern city as of Tuesday evening, cramming onto the enclave’s coastal road, but roughly half a million were believed to still be there. On Wednesday, the military announced the opening of another “temporary route” heading south along Salah al-Din Road. The start of the long-planned ground offensive drew fierce condemnation from allies of Israel and aid agencies, who said it would worsen an already dire humanitarian situation and derail any diplomatic resolution to the nearly two-year war.