By Jana Choukeir and Nadine Awadalla DUBAI (Reuters) -Yemen’s Iran-aligned Houthi group said on Wednesday it would keep up attacks on U.S. and British warships in the Red Sea in what it called acts of self defence, stoking fears of long-term disruptions to world trade. In a statement, the group’s military spokesperson said all American and British warships participating in “aggression” against its country were targets. The U.S. and Britain have launched strikes on Houthi targets in Yemen, and returned the militia to a list of terrorist groups as turmoil from the Israel-Hamas war spreads throug…