On Tuesday evening, an explosion rocked a hospital in northern Gaza where hundreds were sheltering from Israeli airstrikes. The Gaza Ministry of Health blamed Israel for the blast but Israel, the U.S. government and independent security experts said preliminary evidence pointed to a local militant group. WSJ’s Yaroslav Trofimov explains what we know so far about the blast. Further Reading: - U.S., Experts Say Evidence Suggests Palestinian Militants’ Rocket Hit Gaza Hospital  - Live Coverage: Israel-Hamas War  Further Listening: - For Palestinians Trapped in Gaza, There’s No Way Out  - The War Between Israel and Hamas  Learn more about your ad choices. Visit megaphone.fm/adchoices