Tajik border guards have reportedly thwarted two attempts to cross the Afghan-Tajik border by suspected drug traffickers since the night of February 3.
Tajikistan's State Committee for National Security said the last illegal border crossing was prevented early on February 5.
One Afghan national was killed during a shootout. Another Afghan and three Tajiks were detained in one of two separate incidents.
A Tajik soldier was killed in a clash with traffickers along Tajik-Afghan border last month.
Tajik officials say at least 20 illegal border crossings by suspected drug traffickers from Afghanistan were prevented in 2012.
Last year, about three tons of different types of drugs were confiscated from Afghan smugglers.
Tajikistan is a major conduit for the trafficking of heroin and other drugs from Afghanistan to Russia and Europe.
Based on reporting by ITAR-TASS, Interfax