The lioness escaped from its enclosure, sparking a three-hour man hunt

Belgian police have been criticised for shooting dead a young lioness at a zoo on Thursday after it escaped from its enclosure.

The animal was killed at Planckendael Zoo in Mechelen, between Brussels and Antwerp, when it came within 10 metres (33 feet) of the carriage of a tourist train where several visitors had taken refuge.

According to media reports, the lion was able to leave its enclosure on Thursday morning because of a mistake by staff.

Ben Weyts, the minister for animal welfare in the Flemish region, said the death was "terrible and inexplicable," Belga news agency reported.

He said the decision to shoot the lion had been taken "solely" by police, who had intervened to secure the site, and demanded an investigation.

But the zoo's management on Thursday afternoon told the Gazet van Antwerpen newspaper that it took responsiblity for the death.

"As security was compromised, we decided, in consultation with the police, to kill the animal," an official was quoted as saying.

During the three-hour hunt, many visitors hid in staff offices and children on a school trip were stopped from getting off their coach.

The was shot dead after two unsuccessful attempts at anaesthetising it.

Children who arrived at the zoo for a school trip were stopped from getting off their coach

The Belgian association Gaia criticised the "cowboy mentality" of the .

"Since all the safety precautions had been taken, was it necessary to resort to such a drastic measure against the animal?" Gaia chief Michel Vandenbosch told AFP.

Planckendael is one of the three largest zoos in the country.