Customs officials at Zurich airport have seized 262 kilograms of ivory that three Chinese men had dispatched from Tanzania, contraband that may have come from up to 50 elephants, Swiss authorities said Tuesday.

The ivory was found during a security check on July 6 and packed in eight suitcases, Switzerland's customs authority said. It put the estimated black market value at about 400,000 francs ($413,000).

The elephant tusks had been sawed into 172 pieces to fit into the luggage, which was being transported from Tanzania's capital, Dar es Salaam, to Beijing via Zurich. The head of the customs operation at the airport, Heinz Widmer, said officials estimate that the pieces came from 40 to 50 elephants.

Demand from China's rising middle class has been fueling elephant poaching in Africa and illegal trade in ivory, which is turned into jewelry and other decorative items.

The Chinese men were temporarily detained in Zurich and questioned, Widmer said. They could face large fines for violating customs and animal protection rules.

The suitcases also contained 1 kilogram of lion fangs and claws — 21 fangs and 35 claws. They could be used as jewelry or talismans, or as a symbol for strength in Chinese traditional medicine, Widmer said.

The ivory haul, while sizeable, is below the 500-kilogram threshold considered to be a large-scale seizure that indicates the likely involvement of organized crime, according to TRAFFIC, a wildlife trade monitoring organization.

The group, which said that it doesn't speculate on the black-market value of ivory as a matter of policy, said the frequency of large-scale seizures has increased greatly since 2000, with 18 such hauls reported in 2013.

In May, a senior Chinese official made an unexpected pledge to halt the ivory trade inside the country, though it isn't clear how and when that ban might take effect.