A new round of mock terrorism events aimed at improving emergency responses will be staged next April in Connecticut and New Jersey, the Homeland Security Department (search) said Monday.

The department has not identified cities to participate in the exercises, spokesman Brian Roehrkasse said. He said the department is developing a plan for mock emergencies to be depicted in the drills.

More than 8,500 people participated in similar exercises in Seattle and Chicago last May. The drills simulated a dirty bomb explosion in Seattle and a bioterror attack in Chicago.

The exercises cost $16 million and involved more than 100 government agencies at local, state and federal levels.

A department report released in December said the drills revealed communication problems and confusion among emergency responders, as well shortages of medical supplies and hospital rooms.

Roehrkasse said officials from Connecticut and New Jersey volunteered to participate in the drills.

Next year's exercises will mark the third installment of the congressionally mandated Top Officials - or TOPOFF (search) - training exercises. The first round, in May 2000, was in Denver and New Hampshire.

"Our experiences in TOPOFF 1 and 2 helped us adjust our procedures," Homeland Security Secretary Tom Ridge (search) said. "Educating, exercising and equipping crisis and consequence managers and responders remains a national priority."