BEIJING, Sept. 30 (Xinhua) -- A Nigerian man has been detained in Zhuhai City, south China's Guangdong Province, after he was detected carrying more than two kilograms of heroin, according to a statement posted on China Customs' website on Sunday.

The incident occurred at 4:57 p.m. on Sept. 26. Police attention was drawn to the man as he entered the Gongbei Customs hall with his luggage, wearing a pair of weird sandals, the statement said.

Police X-rayed his suitcase and found another pair of strange sandals in it, said the statement.

Further inspection led to the discovery of four packages of yellow and white powder, which was later confirmed to be two kilograms of heroin, concealed in the soles of the two pairs of sandals, it said.

Customs officials did not reveal the name of the Nigerian man or his destination.

Officials say traffickers have come up with more ways to smuggle drugs, which has brought challenges to their detection work in recent years.

Gongbei Customs have cracked a total of 21 drug trafficking cases so far this year, seizing 19.55 kilograms of various illegal drugs.

By June 15 this year, China Customs had seized 229 kilograms of heroin and detained 180 drug trafficking suspects.