Israel on Thursday escalated its response to rocket attacks this week by launching rare airstrikes on Lebanon, the army said.

The army said in a statement that jets struck the launch sites from which rockets had been fired over the previous day, as well as an additional target used to attack Israel in the past. The IDF blamed the state of Lebanon for the shelling and warned “against further attempts to harm Israeli civilians and Israel’s sovereignty.”

The overnight airstrikes were a marked escalation at a politically sensitive time. Israel’s new eight-party governing coalition is trying to keep peace under a fragile cease fire that ended an 11-day war with Hamas’ militant rulers in Gaza in May. Several incidents leading up to this week’s rocket fire from Lebanon have focused attention on Israel’s northern border, and the United States swiftly condemned the attacks on Israel.

The Hezbollah-owned Al-Manar TV reported the strikes at around 2 a.m., saying they hit an empty area in the Mahmoudiya Village in Marjayoun district.

Avichai Adraee, the Israeli army’s Arabic-language spokesman, said the Lebanese government is responsible for what happens on its territories and warned against more attacks on Israel from south Lebanon.

Three rockets were fired from Lebanon into Israeli territory Wednesday and the army responded with sustained artillery fire, Israel’s military said. The announcement came after sirens sounded in northern Israel warning of a possible rocket attack. Two rockets landed inside Israeli territory, the army said.

Channel 12 reported that one rocket exploded in an open area and another was intercepted by Israel’s defense system, known as the Iron Dome. Israeli media reported that the incoming rockets started fires near Kiryat Shmona, a community of about 20,000 people near the Lebanese border.

The Lebanese military reported 92 artillery shells fired by Israel on Lebanese villages as a result of the rocket fire from Lebanon. It said the Israeli artillery shelling resulted in a fire in the village of Rashaya al-Fukhar. In a statement, the Lebanese army also said it was conducting patrols in the border region and had set up a number of checkpoints and opened an investigation to determine the source of the rocket fire.

Lebanese security officials did not immediately confirm the Israeli airstrikes.

There have been several similar incidents in recent months.

U.S. State Department spokesman Ned Price condemned the rocket fire from Lebanon.

“Israel has the right to defend itself against such attacks,” he told reporters in Washington, adding that the U.S. would remain engaged with partners “in the region in an effort to de-escalate the situation.”

At the United Nations, spokesman Stephane Dujarric said the U.N. peacekeeping mission in Lebanon, known as UNIFIL, was aware of the rocket fire and Israel’s artillery response. He said the UNIFIL commander, Maj. Gen. Stefano Del Col, appealed for a cease-fire and urged both sides to “exercise maximum restraint to avoid further escalation.”