Russians make bomb arrests
Several suspects have been arrested over the three bombings in southern Russia that killed at least 21 people and injured more than 100 others.
The head of the Federal Security Service, Nikolai Patrushev, says at least six other suspects are being sought.
Police released sketches based on witnesses accounts of the men wanted for the attacks.
Three bomb-laden cars exploded almost simultaneously on Saturday in three towns near Chechnya in the worst act of terror to hit the region in months.
We can already say that these three crimes were connected, there have been arrests," Mr Patrushev said on NTV television.
"These are people who have information about how this terrorist attack was prepared."
The worst blast hit Saturday morning near a bustling farmer's market in the city of Mineralnye Vody.
Nineteen people were killed in the blast that is said to have been caused by a car bomb detonated by remote control.
Seventy victims remain in hospital, with eight reported in a critical condition.
The scenes of the blasts, Mineralnye Vody, Yessentuki and Adyge-Khabl, are located within 160 kilometres (100 miles) of Chechnya. They are about 300 kilometres (180 miles) southeast of the city of Rostov-on-Don.
