US Secretary of State John Kerry has offered a US$1 million reward to help smash a Laos-based poaching network slaughtering endangered elephants and rhinos for their precious horns and tusks. The reward, the first of its kind by the department, targeted the Xaysavang network, operating from Laos to as far afield as South Africa, Mozambique, Thailand, Malaysia, Vietnam, and China. "The involvement of sophisticated transnational criminal organisations in wildlife trafficking perpetuates corruption, threatens the rule of law and border security in fragile regions," Kerry said on Wednesday. He estimated that annual profits from wildlife trafficking reached up to US$10 billion and were pumped into other "illicit activities such as narcotics, arms, and human trafficking". Another effect of poaching was that it "destabilises communities that depend on wildlife for biodiversity and eco-tourism", he said in the statement. Offering the department's first reward under its transnational organised crime rewards programme, Kerry said the Xaysavang network "facilitates the killing of endangered elephants, rhinos, and other species for products such as ivory". He revealed that several major seizures of illegal wildlife products had been traced back to the network. The lucrative Asian black market for rhino horn, used in traditional medicine, and ivory has driven a boom in poaching across Africa. Police in Zanzibar on Wednesday said they had seized a 12-metre container hiding an estimated several tonnes' worth of ivory. The seizure comes as authorities in Tanzania crack down on poaching amid a surge of killings of elephants and rhinos.