Israeli Prime Minister Benjamin Netanyahu said Sunday that Iran would pay "a very heavy price" for killing Israeli civilians, as the two foes kept up intense fighting.

"Iran will pay a very heavy price for the premeditated murder of civilians, women and children," Netanyahu said during a visit to the site of a missile strike on a residential building in the coastal city of Bat Yam, near Tel Aviv.

Iran's missile attacks on Israel Saturday night and early Sunday killed 10 people and wounded more than 200, according to first responders, bringing the total number of fatalities from Iranian strikes to 13.

Missiles that broke through Israel's air defense system also caused damage and destruction in several areas, including Bat Yam, Tel Aviv and in the country's north.

Israel's military censorship forbade journalists from sharing footage or the exact locations of missile hits inside the country.

"Israel absolutely had to carry out this operation," Netanyahu said in reference to the waves of strikes carried out across Iran on military and nuclear sites since Friday morning.

The operation, dubbed "Rising Lion", officially aims to keep Iran from acquiring a nuclear weapon, and has hit more than 250 targets, according to Israel's military.

"We will reach all our objectives and we will eliminate the double existential threat," Netanyahu added, referring to Iran's nuclear program and its ballistic missile capabilities.