Tourists crossing a new bridge built across Venice's Grand Canal have stumbled across a possible flaw, which has landed 10 of them in casualty with twisted ankles and other minor injuries.

The 10 tourists were treated after taking a tumble on the 94-metre long Constitution Bridge, designed by the Spanish architect Santiago Calatrava, which opened on September 11.

Pedestrians who lost their footing have blamed the bridge's irregularly spaced steps, some of which act as viewing points, and the disorienting optical effect of the sectioned stone and glass flooring. "People miss a step and then they come and moan at us," a police guard on 24-hour security watch at the sleek steel and glass bridge told the Italian newspaper Corriere della Sera. But one of the city's doctors, Paolo Pennarelli, suggested the mishaps were partly due to tourists marvelling at the bridge's impressive views over the lagoon city rather than paying attention to their feet. "We have quite a lot of this type of accident every week. In Venice, falls like this are natural," he said.

Venice city council has asked Calatrava for suggestions to remedy the problem, but has so far ruled out closing the bridge for structural modifications.

"We'll intervene with some sort of signalling system for distracted tourists, perhaps with stickers on the ground," Salvatore Vento, Venice's head of public works, told Corriere.

This is the latest in a series of setbacks for the bridge, which has been criticised for delays and cost overruns.