Mexico City - Mexican authorities seized almost half-a-tonne of cocaine Friday at the Mexico City airport, after it arrived in 20 boxes transported on a commercial flight from Bogota, authorities said.

The drugs, weighing 477 kilogrammes, were hidden inside phone and address books found in the warehouse of an undisclosed airline, the Mexican Public Security Ministry said.

The confiscation of cocaine and chemical substances for the production of synthetic drugs has increased at Mexico City's airport since last year. In December 2007, five customs officers employed at the airport were beheaded, reportedly in connection with vendettas by drug gangs. (dpa)