Palestinians in Gaza have fired scores of rockets and mortar bombs into southern Israel, prompting retaliatory air strikes, a day after an Israeli incursion prompted deadly fighting in the enclave.
Three Palestinian gunmen were killed in the air attacks. Warplanes also destroyed the premises of Hamas's Al-Aqsa Television, the Israeli military said.
On the Israeli side of the border, a guided missile wrecked a bus, wounding a soldier, and shelling struck several homes as residents fled to shelters.
The flare-up cast a new cloud over efforts by Egypt, Qatar and the United Nations to broker a long-term ceasefire between Israel and Hamas, the dominant Islamist group in Gaza.
The enemies have fought three wars in the past decade. On Sunday, Israeli Prime Minister Benjamin Netanyahu said he hoped to reach an "arrangement" to avoid another conflict and ease Israeli-blockaded Gaza's economic hardships.
The United States, whose attempt to seal a wider Israeli-Palestinian peace stalled in 2014, condemned Hamas.
"We stand with Israel as it defends itself against these attacks," US envoy Jason Greenblatt tweeted.
"This violence prevents any real help for the people of Gaza."
In southern Israel, interceptor missiles streaked through the sky and sirens sounded during what the military said were around 300 rocket and mortar launches from Gaza.
Israeli medics said at least 10 people were hurt, while in Gaza, medics said three people were wounded.
The frontier had been quiet earlier in the day after a botched Israeli undercover operation in Gaza led to fighting that killed a Hamas commander, six other Palestinian militants and an Israeli colonel.
Late on Sunday, Palestinians shelled Israel in response to the Israeli incursion and air strikes, which Hamas said were intended to cover the retreat of the Israeli commandos' car.
The military said a lieutenant-colonel had been killed in the raid and another officer wounded.
Violence has flared regularly along the Israel-Gaza border since Palestinians began protests on March 30 to demand rights to land lost to Israel in the 1948 war of its creation.
Israeli gunfire has killed more than 220 Palestinians since the start of the demonstrations, which have included breaches of the border fence.
