Bulgarian police have seized 108 kg of amphetamine and arrested nine people, including two Jordanians and a Syrian national, suspected of involvement in illicit drugs trade.

The other six of the detained are Bulgarian citizens, some of them have criminal records, according to a statement released by the Ministry of the Interior on Friday.

The arrests were made in the city of Plovdiv on Thursday. Police found nearly 50 kilogrammes of the synthetic psychoactive drugs in a car used by the suspects.

The remaining amount of amphetamine was discovered during a subsequent police search of a building in the village of Petarch, on the northern outskirts of Sofia.

The Bulgarian citizens were the sellers of the amphetamine pills, the foreign nationals were the buyers, according to public TV channel BNT.

The amphetamine market is growing in the Middle East, with busts mostly in Saudi Arabia, Jordan and Syria accounting for more than half of amphetamines seized worldwide, according to United Nations data for 2014.