"Many have been killed -- including women and children, as well as UN staff," Ban said in a statement.
Gaza's emergency services said 15 people were killed and more than 200 injured when an Israeli shell slammed into the school run by the UN agency for Palestinian refugees (UNRWA).
Ban said he was "appalled" by the news and "strongly condemned" the attack on the school in Beit Hanun, in the northern Gaza Strip.
"Today's attack underscores the imperative for the killing to stop -- and to stop now," he said in the statement released in Iraq, his latest stop on a tour to try to secure a ceasefire in Gaza.
The Israeli army said it would investigate the circumstances surrounding the school attack.
You’ve hit your limit of 5 free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →Subscribe to Business Standard digital and get complimentary access to The New York Times
Smart Quarterly
₹900
3 Months
₹300/Month
SAVE 25%
Smart Essential
₹2,700
1 Year
₹225/Month
SAVE 46%
Super Saver
₹3,900
2 Years
₹162/Month
Subscribe
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Access to Exclusive Premium Stories Online
Over 30 behind the paywall stories daily, handpicked by our editors for subscribers
Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share
Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor
Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements
Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
SAVE 25%