KUALA LUMPUR, Malaysia — Three Iranians were detained at Malaysia's main airport after $4 million worth of illegal drugs were found in their luggage, in the nation's biggest drug haul in three years, reports said Sunday.

The 120 pounds (54.5 kilograms) of methamphetamine was in plastic bags stuffed among clothes in two hand-carried suitcases, The Star newspaper quoted customs investigations director Zainul Abidin Taib as saying.

It said customs officers detained the man and two women at the Kuala Lumpur International Airport upon their arrival late Friday from Dubai. They have not been charged. The death penalty is mandatory for drug trafficking in Malaysia.

The drugs were estimated to be worth 13.6 million ringgit ($4 million), the reports said. The New Straits Times newspaper said it was the biggest drug haul in three years and that 10 Iranians now have been detained on suspicion of smuggling drugs into Malaysia this year.

"This is a worrying sign as we do not want our airports to become an easy target for drug smugglers," Zainul was quoted as saying.

Last year, customs officials detained 41 foreign suspected drug traffickers, including 29 Indians and seven Iranians.

Zainul and other customs officers could not immediately be reached Sunday for comment. (AP)