Kenya's wildlife minister on Tuesday apologised for telling his critics to "go to hell" as he comes under mounting pressure over the death of 10 rhinos during a botched transfer.Tourism and Wildlife Minister Najib Balala had directed the comments to those calling for his resignation over the fiasco during a press conference on Monday."People need explanations about the rhinos... people are angry. I am also angry," Balala told lawmakers on Tuesday."I have emotions and I reacted. I feel let down by my system that did not act quickly to stop the death of the rhinos."Kenyans have been left stunned after 10 of 11 rhinos being transferred from Nairobi and Lake Nakuru national parks to Tsavo East died after the operation.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTER FOLLOW News24 Africa on Twitter and FacebookThe 11th was attacked by lions, and is recovering.Balala has blamed Kenyan Wildlife Service (KWS) officials involved in the transfer for "negligence", suspending six senior officials.An initial enquiry indicated that the rhinos may have become dehydrated and died after drinking saline water in their new habitat.The scandal intensified when the former chairperson of the KWS board, the world-renowned anthropologist Richard Leakey, released a statement revealing that the board had on three prior occasions blocked the transfer.He said this was due to "a deep concern about the lack of vegetation in the sanctuary that could sustain rhino, and also, the real issue of available and safe water."He also indicated that no new KWS board had been set up in the three months since the one he chaired expired, leaving the decision to carry out the translocation entirely up to Balala's ministry.As furious Kenyans on social media demanded to see the horns of the dead rhinos, KWS displayed the 20 horns to the media last week to allay suspicions.In yet another blow to the country's rhino population, the KWS said that a 12-year-old male had been killed by poachers for its horn in Nakuru National Park on Monday night.Save the Rhinos estimates there are fewer than 5 500 black rhinos in the world, all of them in Africa, while Kenya's black rhino population stands at 750, according to the Worldwide Fund for Nature.Rhinos have few natural predators because of their size and thick skin but are targeted by poachers for their horns which are highly valued in parts of Asia where they are believed to have medicinal qualities.