The city said it plans to tighten safety procedures for the Macy's Thanksgiving Day parade after two spectators were injured last year by a giant balloon that got caught on a street lamp.

The new rules were recommended on Tuesday by a task force directed by Mayor Michael Bloomberg.

The accident happened in Times Square, where tethers from the M&M's Chocolate Candies balloon became entangled on the head of a street lamp. Two sisters were hit by the debris and suffered cuts and bruises.

Among its recommendations, the task force said adjustments should be made to the formula for assessing safe passage of each balloon. Previously, organizers had assumed a uniform measurement of 62 feet (18.90 meters) for the width of the parade path. But the path varies in several places, and the M&M's balloon was traveling through an area 39 feet (11.90 meters) wide at the time of the accident.

The panel also recommended improving the method of assessing wind speeds. Chief handlers for some balloons carried hand-held wind measuring instruments, or anemometers. But Bloomberg's task force said wind speeds could be more accurately assessed if anemometers were installed at major intersections, taking several measurements over time.

The city said Macy's, which sponsors and runs the parade, cooperated with the probe and reimbursed the city for some of the consultant costs.

In 1997, two people were seriously hurt as a Cat in the Hat balloon slammed into a metal pole.