Israel fired airstrikes at Lebanon and the Gaza Strip around 1 a.m. Friday morning, targeting Hamas, the Palestinian militant group that runs Gaza. The attacks were following rockets that fired from Lebanon into Israel Thursday night and appeared to be a retaliatory attack.

“Israel’s reaction, tonight and in the future, will exact a significant price from our enemies,” Benjamin Netanyahu, the Israeli prime minister, said in a statement after the Israeli warplanes hit Gaza, per The New York Times.

According to NBC News, “No group claimed responsibility for the attacks from Lebanon, although Israel pinned the blame on Hamas.”

Some analysts described the crossfire “as the most serious cross-border violence since Israel’s 2006 war with Lebanon’s Hezbollah militants,” per The Associated Press.

Were the rockets in response to Israeli raids earlier in the week?

The violence largely died down by sunrise on Friday. But there was a shooting near an Israeli settlement carried out later in the day that killed two Israeli sisters “that is being investigated as a terrorist attack,” according to The Washington Post.

Earlier in the week, Israeli police raided the Al-Aqsa Mosque in the Old City in Jerusalem, and the rocket attacks are assumed to be retaliation for the raid “that had prompted widespread anger among Palestinians,” the Times reported.

The hilltop compound in the Old City is considered a holy site for both Muslims and Jews. It’s not currently under full Israeli control, but Palestinians “fear that Israel plans to one day take over the site or partition it,” according to the AP.

Israeli officials argue they don’t intend on changing the current situation, which has kept the site a shared holy site since 1967, but the country “is currently governed by the most right-wing government in its history,” per the AP.