Copenhagen, Dec 7 : The sheer weight of numbers -- 15,000 delegates from 192 governments, NGOs and media -- threatened to overwhelm the organisers as the UN climate summit opened here Monday.

The 15th summit of the UN Framework Convention on Climate Change (UNFCCC) saw serpentine queues at all entry points right from the eve of the summit opening.

Matters were not helped by a bomb scare at the main entrance of Bella Centre Sunday afternoon when hundreds of delegates were in the queues to get their conference badges.

The scare was due to an empty bag, but it meant the area had to be evacuated and the bomb disposal squad called in, while delegates waited out in the cold.

The effect of that delay continued through the evening and Monday, as it took an average of two hours to get a badge. Many delegates missed the opening.

Security at this conference is even tighter than it would otherwise be in a place where 110 heads of state and government are expected.

Danish police have reports that a group of anarchists unhappy with lack of progress in the days before the summit plan to "invade" the city.

Local media says the authorities here have hired an empty warehouse, where they have put a large number of "cages" for the anarchists and anyone else found to be "misbehaving".

But despite all this, the conference is hoping to do its bit to fight climate change.

The organisers have made it a point not to have any bottled water anywhere at Bella Centre, relying for drinking water on the municipal water supply instead. At least two-thirds of the food on sale is organic.(IANS)