A Yemeni man walks on debris from a destroyed building after it was struck by U.S. airstrikes in Sanaa, Yemen, on Monday. The Associated Press

A new American airstrike campaign against Yemen’s Houthi rebels appears more intense and more extensive, as the U.S. moves from solely targeting launch sites to firing at ranking personnel as well as dropping bombs in city neighborhoods, an Associated Press review of the operation shows.

The pattern under U.S. President Donald Trump reflects a departure from the Biden administration, which limited its strikes as Arab allies tried to reach a separate peace with the group. It comes after the Iran-backed Houthis threatened to resume attacking “any Israeli vessel” and have repeatedly fired at Israel over the country’s refusal to allow much-needed humanitarian aid into the Gaza Strip.

The Houthi attacks and the response to them have drawn new scrutiny in Washington after security officials in Trump’s administration shared plans for the first round of strikes on the rebels in a group chat that included a journalist. But bombing alone may not be enough to stop the Houthis, whose earlier barrage of missile fire toward the U.S. Navy represented the most intense combat it had seen since World War II.

Meanwhile, concerns are growing over civilians being caught in the middle of the campaign. While the U.S. military has not acknowledged any civilian casualties since the strikes began over a week ago, activists fear strikes may have killed noncombatants already in territory tightly controlled by the Houthis.

“Just because you can’t see civilian harm doesn’t mean it’s not happening,” warned Emily Tripp, the director of the U.K.-based group Airwars, which studies Western airstrike campaigns.