The invitation comes after tensions over the detention of seven Tajiks suspected of the March 22 attack in Moscow, which led Tajikistan to denounce the violation of the rights of its citizens in Russia.

During a telephone conversation, Putin and Rakhmon discussed "cooperation in the fight against terrorism and in the area of migration," according to a statement from the Kremlin cited by the French agency AFP.

The two leaders also "discussed in detail issues of cooperation in the area of migrant workers" and highlighted the "close coordination" of their respective security forces, the Tajik presidency said in a separate statement.

Russia will mark the day of victory over Nazi Germany on Thursday, May 9, with military parades in 25 cities, including Moscow, whose Red Square will host the main ceremony.

More than a million Tajiks live, work or study in neighboring Russia, where the standard of living is higher than in the former Soviet republic of Tajikistan.

Since the attack on the Crocus concert hall, citizens of Central Asian countries, starting with Tajikistan, have been under close surveillance by the Russian authorities.

Tensions reached a peak last weekend when hundreds of Tajiks were held for hours at passport control at Moscow airports.

Emomali Rakhmon at the time denounced violations of the rights of Tajiks by the Moscow authorities, which were refuted by the Russian Foreign Minister.

Sergei Lavrov on Tuesday justified the measures with the need for reinforced controls following the March 22 attack, and rejected the idea that they specifically targeted Tajiks.

In the statement released today, the Kremlin accused "certain unidentified forces" of wanting to "artificially aggravate" the situation of migrant workers.

The attack on the concert hall on the western outskirts of Moscow caused at least 144 deaths and 360 injuries.

Four Tajiks were quickly detained and taken to court after having been visibly beaten, which aroused strong emotions in Tajikistan.

The 'jihadist' group Islamic State, also known by the Arabic acronym Daesh, claimed responsibility for the attack.

Russia, after accusing Ukraine, admitted that the attack had been perpetrated by "radical Islamists," without abandoning the idea of Ukrainian involvement.

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