Russian police and troops carried out a huge security operation in the country's turbulent south yesterday after a series of bomb attacks as local authorities prepared to bury the dead.
At least 21 people were killed and 142 injured by three blasts on Saturday near Chechnya. Officials blamed separatist guerrillas, and President Putin called for "the toughest measures" against them.
"Everything possible is being done to capture the bandits," a duty officer at the regional crisis centre set up by Mr Putin's envoy in southern Russia said.
An Interior Ministry officer in the town of Mineralnye Vody in the Stavropol region, where a booby-trapped car killed 19 people and injured more than 100 at a busy street market, said a stepped-up police presence was evident everywhere.
A car explosion in the Stavropol town of Yessentuki injured more than a dozen people, and two police bomb experts died in the neighbouring republic of Karachayevo-Cherkessia while trying to defuse another boobytrapped car.
Typically for Russia, no one has claimed responsibility for the blasts, but the Prosecutor General Vladimir Ustinov said he believed the prominent Jordanian-born rebel commander, Khattab, to be behind the bombings.