Update(1930ET): The US has just confirmed it conducted a second round of major airstrikes in Syria since the Gaza war began, which the Pentagon has described as retaliation for a recent series of attacks by "Iran-linked" militias against US troops in the country's east:

U.S. fighter jets conducted "a self-defense strike" at a weapons storage facility in Syria that was being used by Iran's Islamic Revolutionary Guard Corps, Defense Secretary Lloyd Austin said Wednesday.

The strike in eastern Syria was carried out at President Joe Biden's direction, Austin said in a statement.

"This precision self-defense strike is a response to a series of attacks against U.S. personnel in Iraq and Syria by IRGC-Quds Force affiliates," Austin said.

At this point the Pentagon has cited that 46 US service members have been injured over the past month of attacks inside Iraq and Syria, most with 'traumatic brain injuries'.  

Update(11:45ET): Yemen's Houthis have claimed they've successfully shot down a US MQ-9 reaper drone over "territorial waters" off the Yemeni coast. According to a machine translation of a Houthi army statement: 

Our air defenses were able to shoot down an American MQ9 aircraft while it was carrying out hostile, monitoring and spying activities in the airspace of Yemeni territorial waters and within the framework of American military support for the Israeli entity.

If confirmed as accurate, this could draw the United States deeper into what could develop into a broader regional conflict. The Pentagon has had aerial assets flying over Gaza, and the Mediterranean and Red Seas. Further US warships have been seeking to intercept ratcheting drone and missile attacks from the Houthis, with one such intercept having already occurred in the opening weeks of the Gaza war, now having reached one month.