The incident comes with bilateral relations already strained by accusations and counteraccusations about purported activities by militants seeking to stir up trouble for both countries.
The press-uz.info website claims Murodullo Zhuraev was detained for unrelated in Surkhandarya's Bandykhan district and is currently being interrogated.
It quotes Uzbek security officials as saying Zhuraev admitted to being a convicted Tajik drug trafficker who agreed to fulfill this mission in return for money and a promise to not be given an additional jail term.
Zhuraev reportedly told investigators that after giving him proper military training, the Tajik Interior Ministry ordered him to Uzbekistan with a view to committing murders there. He also allegedly confessed to being instructed to recruit people to carry out terrorist attacks in Tajikistan.