Qatari, Egyptian and US mediators called on Israel and Hamas Saturday to "finalise" the truce deal.
Advocates of the two-state solution have envisaged a Palestine in the Gaza Strip and West Bank linked by a corridor through Israel.
Survivors said families were preparing to sleep when the strike hit the Tel Al-Sultan neighbourhood where thousands were sheltering after Israeli forces began a ground offensive in the east of Rafah over two weeks ago.
While the International Court of Justice, or World Court, has no means to enforce its orders, the case was a stark sign of Israel's global isolation over its campaign in Gaza.