British zoos should be subject to a "central licensing" system, a charity dedicated to animals said after the deaths of two tigers last week.
A tiger from the London Zoo was killed by a potential mate and another died after tigers fought in a safari park.
The Born Free Foundation has stated that the zoo licensing rules currently supervised by local authorities have "differences of understanding and application".
The zoo's trade organization said that tiger deaths were not related to licenses.
The Born Free Foundation, which campaigns for the maintenance of wildlife in the wild, says that "significant incidents occur at a disturbing frequency" in zoos.
He said he has recorded 33 incidents since 2016, including the death of eight Humboldt penguins as a result of an "urban fox" attack and a snow leopard escaped, shot after a zookeeper left an open door.
Chris Draper, responsible for animal welfare and captivity, said that "the licensing and inspection of zoos in Britain are currently the responsibility of a large number of local authorities ".
This leaves the law "open to interpretation", he said.
& # 39; Important conservation work & # 39;
The professional body that represents more than 100 zoos and aquariums says it is "saddened to learn of the deaths of two tiger women at two gatherings of its members in recent days".
But the British and Irish Association of Zoos and Aquariums (BIAZA) rejects the call of Born Free in favor of a license amendment, stating that the events should not overshadow the important conservation work undertaken by its members.
"BIAZA Welcomes Robust Zoo Licenses and Approves Recent Actions by Defra [Department for Environment, Food and Rural Affairs] strengthen the zoo licensing process in the UK, "added a spokeswoman.
An endangered Sumatran tiger was killed by a potential mate during his first introduction to London Zoo on February 8th.
The zoo said staff used horns and fire extinguishers to prevent the male tiger, Asim, from killing Melati.
However, despite the efforts of veterinarians, 10-year-old Melati died.
On Monday, a rare tiger of love died during a fight with two other tigers at Longleat Safari and Adventure Park in Wiltshire.
According to the park, Shouri, a 13-year-old woman, was killed after gaining access to an enclosure where two other tigers, Red and Yana, were being held. A fight took place between the three animals.
The park said that a full investigation was under way to determine the exact circumstances surrounding "this terribly sad event".
It is thought that there are only 300 Sumatran tigers and 540 wild tigers left in the wild.
Defra has been contacted for comments but has not yet responded.