PITTSBURGH — The Secret Service will design, coordinate and implement a security plan for the Group of 20 summit.

Thousands of demonstrators and media will accompany 19 heads of state when they descend on Pittsburgh on Sept. 24 and 25 to discuss the global economic crisis.

Secret Service spokesman Malcolm Wiley says the Department of Homeland Security declared on Tuesday the summit a national special security event. The designation makes the Secret Service the lead agency for security issues.

Wiley says the Secret Service will appoint committees to address issues. A subcommittee will try to determine how many protesters will arrive.