Updated

Turkey was holding a suspicious shipment bound for Venezuela from Iran because it contained lab equipment capable of producing explosives, a customs official said Tuesday.

Suleyman Tosun, a customs official at the Mediterranean port of Mersin, said military experts were asked to examine the material, which was seized last month, and decide whether to let the shipment to go to Venezuela.

Authorities detected the equipment during a search of 22 containers labeled "tractor parts," Tosun said. They were brought to Mersin by trucks from neighboring Iran, he said. Turkey's Interior Ministry said an investigation was under way.

"Experts from Turkey's Atomic Institute determined there were no traces of radioactive material, but said the equipment was enough to set up an explosives lab," Tosun said. "We have asked the military to send experts to determine whether to resume the shipment."

Some barrels, labeled with "danger" signs, contained chemicals. Tosun said details were still unclear.

An Iranian embassy official, speaking on condition of anonymity because he was not authorized to speak to the media, said the shipment contained "nothing important."

Iran and Venezuela operate various joint ventures in Venezuela, including plants to assemble tractors and cars. The two countries also have agreed to team up on petrochemical projects.