As concerns about the escalating risks for commercial shipping deepen following the attack on three vessels in the region on Sunday, war risk insurance premiums for trips across the Red Sea have increased, according to maritime and insurance sources on Monday.

Following the start of a bloody conflict between Israel and the Palestinian Islamist organization Hamas on October 7, these occurrences represent the most recent in a string of attacks in Middle Eastern seas.

The U.S. Navy reported on Sunday that the three commercial vessels were attacked in southern Red Sea international waters.

Yemen’s Iran-backed Houthi group claimed drone and missile attacks on what it said were two Israeli vessels in the area.

“It has now become clear the Houthis will attack anything at sea with links to Israel or Israelis, regardless of how feeble the links may be, and regardless of the potential for collateral damage to non-Israelis, for example crew members,” Jakob Larsen, head of maritime safety & security with shipping association BIMCO, told Reuters.

Israeli military spokesperson Rear Admiral Daniel Hagari said the two ships cited by the Houthis had no connection to Israel. U.S. Central Command said the three vessels were connected to 14 separate nations.

Larsen said the industry would welcome a strengthened naval presence in the area.

“Faced with a threat from military formations such as the Houthis, merchant ships rely on protection from naval units,” he said.