US officials have quietly suggested ways Israel could reduce civilian casualties in its campaign to eradicate Hamas in the Gaza Strip, including using smaller munitions.

During his second Middle East visit in less than a month, U.S. Secretary of State Antony J. Blinken spoke to Israeli Prime Minister Benjamin Netanyahu on Friday about “concrete steps that can and should be taken” to minimize civilian deaths.  

Blinken didn’t go into detail about what those steps would be. State Department Spokesman Matthew Miller also wouldn’t elaborate.

U.S. officials, however, speaking anonymously to The New York Times, said the methods included improving how Israel targets Hamas leadership, gathering more intelligence before launching strikes and deploying ground forces to separate civilian population centers from the terrorists.

The United States also proposed using smaller bombs to destroy Hamas’s tunnels.

About 90% of the bombs Israel dropped in the first two weeks of the war were in the 1,000 to 2,000 pound range, the Times reported, citing a senior U.S. military official. The remainder were 250-pound bombs.