The U.N. Security Council is set to hold an emergency meeting Wednesday to discuss security in the Red Sea following a series of attacks by Yemen-based Houthi militants on vessels in the key waterway.

The Houthis have launched drone, missile and boat attacks since October, targeting what they say are vessels linked with or traveling to Israel. The militants say they are acting in solidarity with Palestinians in Gaza.

“The numerous unjustified attacks originating from Houthi-controlled territories in Yemen are a grave threat to international commerce and maritime security,” U.S. Mission to the United Nations spokesperson Nate Evans said in a statement.

The attacks have drawn military responses from U.S. and British forces and prompted the United States to set up a coalition of countries to try to protect the shipping lanes.

A number of commercial cargo companies have altered their operations, sending ships away from the Red Sea and its access to the Mediterranean through the Suez Canal and instead using a longer route around the southern tip of Africa.

U.S. Central Command reported a new Houthi attack late Tuesday, saying the militants fired two anti-ship ballistic missiles from Yemen into the southern Red Sea.

A CENTCOM statement said multiple commercial ships in the area reported the missiles landed in the water, and that there were no reports of damage.

“These illegal actions endangered the lives of dozens of innocent mariners and continue to disrupt the free flow of international commerce,” CENTCOM said. “This is the 24th attack against merchant shipping in the Southern Red Sea since Nov. 19.”