KAMPALA (Reuters) - An American woman who was kidnapped with her driver at Uganda’s most popular wildlife park by gunmen had failed to take an armed ranger as required by the park’s regulations, a spokesman for the country’s wildlife authority said on Thursday.

Kimberley Sue Endecott, 35, and Ugandan driver Jean Paul were on a game drive in Queen Elizabeth National Park when four gunmen ambushed their vehicle on Tuesday evening, police said.

An elderly couple also at the scene were not taken and raised the alarm.

Various illegal groups from Somali militant Islamists to Congolese-based rebels sometimes operate in Uganda, but the kidnappers’ identity was not known.

“We have armed ranger guides, if you’re going out on a drive in the park you’re supposed to have one but these tourists went out on their own without a guard,” Bashir Hangi, spokesman for the state-run Uganda Wildlife Authority (UWA), told Reuters.

“From their camp in the park, they just got into a vehicle and went out. They should have notified us and informed us that they’re going out for a game drive and then we would have availed them a guard but they didn’t do this.”

California-based Endecott and the couple entered Uganda on March 29 and flew the next day to the park in the country’s southwest, the spokesman added.

There was no immediate comment on the progress of the investigation by Ugandan authorities.