GENEVA- Yemen's humanitarian situation has worsened rapidly since U.N. peace talks collapsed and fighting resumed in the port city of Hodeidah, where hundreds of thousands of lives hang in the balance, the top U.N. aid official in Yemen said on Thursday.

"The situation has deteriorated dramatically in the past few days. Families are absolutely terrified by the bombardment, shelling and airstrikes," U.N. humanitarian coordinator Lise Grande said in a statement.

"The mills in Hodeidah feed millions of people. We’re particularly worried about the Red Sea mill, which currently has 45,000 metric tonnes of food inside, enough to feed 3.5 million people for a month. If the mills are damaged or disrupted, the human cost will be incalculable," she said.

(Reporting by Tom Miles Editing by Matthew Mpoke Bigg) ((tom.miles@thomsonreuters.com; +41 58 306 2006; Reuters Messaging: tom.miles.reuters.com@reuters.net))