Israel launched a series of missile strikes at southern Lebanon early Friday, in an offensive that The New York Times declared the worst cross-border conflict in nearly 20 years. Israel also set off a simultaneous grueling bombing campaign in the Gaza Strip that damaged, among other targets, a pediatric hospital, the Times reported. The escalating tensions come after Israeli authorities raided Jerusalem’s Al-Aqsa Mosque compound—a holy site for both Jews and Muslims—and arrested more than 300 people Wednesday. In response, Israel says it sustained rocket fire Thursday from pro-Palestinian militias in Lebanon—prompting Friday’s strikes. “Israel’s reaction, tonight and in the future, will exact a significant price from our enemies,” Israeli Prime Minister Benjamin Netanyahu said in a statement.