Israeli forces have pushed towards the heart of Gaza City, risking the lives of Palestinians who had stayed put in hopes that growing pressure on Israel for a ceasefire would mean they would not lose their homes, Reuters reports.

The Israeli government has urged the population of Gaza City to move south, but many people hesitated, citing the lack of security and widespread hunger there.

“We moved to the western area near the beach, but many families didn’t have the time, tanks took them by surprise,” said Thaer, a 35-year-old father of one from Tel Al-Hawa.

Medics said at least 20 people were killed and many others wounded when Israeli airstrikes hit a shelter housing displaced families near a market in the middle of the city. Two other people were killed in a house nearby, they said.

“We were sleeping in God’s care, there was nothing — they did not inform us, or not even give us a sign — it was a surprise,” said Sami Hajjaj.