Cop15 security operation will be biggest for 20 years, Montreal police say

Protests against oil and mining have been planned, as thousands of delegates arrive for UN biodiversity summit

Police in Montreal are bracing for their biggest operation in two decades, as thousands of visitors - including frustrated demonstrators - begin to arrive for the Cop15 global biodiversity summit.

Officials are expecting more than 10,000 people, including scientists and senior bureaucrats, to attend Cop15 in the Canadian city.