Hunters have claimed a successful day of "legal" hunting and protest against the hunting ban in England and Wales.
Up to 270 hunts were out in England and Wales
But anti-hunt campaigners said there had been widespread intimidation of activists monitoring hunts.
Countryside Alliance chairman John Jackson said Saturday had been a "massive demonstration by the rural community of support for hunting".
The League Against Cruel Sports claimed the new act had been broken but said the numbers of foxes killed had fallen.
Mr Jackson told BBC News people turned out "to show en masse that the Hunting Act was a bad law".
He said foxes and other animals had been killed "legally, so far as I know".
Thousands of hunt supporters turned out at 270 hunts around the country on the first day of the ban, with anti-hunt groups sending out 100 monitors to check the law was not being broken.
WAYS TO HUNT LEGALLY
Hunting rabbits or rats instead of foxes or hares
Using no more than two dogs to flush out a fox to be shot
Drag or trail hunting (using an artificial scent to hunt with hounds)
Using hounds to flush out a mammal to be hunted by a bird of prey
Exercising packs of hounds without using them to hunt
Using terriers to flush and shoot foxes, to protect gamebirds
There were only four arrests - over hunting hares in Wiltshire - although it was not clear whether they were made under the Hunting Act.
They have been released on bail but police say they may face prosecution under new poaching laws.
One anti-hunt protester was taken to hospital after a violent clash in Kent.
The man suffered facial injuries after an incident involving a group of men at the end of the East Kent Hunt, near Ashford.
Monitor Penny Little, who monitored the Bicester Hunt in Oxfordshire, said she had witnessed "gratuitous, spiteful killing of foxes".
"If the hunting fraternity go out into the field and commit offences and attempt to run circles around this law, there is only one development that can occur from that, and that is a tightening of the law," she said.
Although hunting with dogs is now a criminal offence, exercising hounds, chasing a scent trail and flushing out foxes to be shot are still legal.
Mr Jackson, who had been at the Bicester hunt, denied there had been any intimidation.
Health Secretary John Reid said "people would be well-advised to follow the guidance of the Countryside Alliance" and hunt within the new law.
"When Parliament has spoken on a free vote, I think most people in this country recognise the law has to be obeyed," he told Sky News' Sunday with Adam Boulton.
Mike Hobday, from the League Against Cruel Sports, said video evidence of the law being broken would be passed onto police.
But he said the figure of 91 foxes killed - reported in some newspapers - would be a major reduction from the 400 killed on a typical Saturday during the season.
He said intimidation seemed to have been widespread and called on hunts to do more to stop their supporters intimidating anti-hunt activists videoing hunts.
"Being reluctant to have their activities being filmed is not a very good way of building public confidence."