The attack on Health Minister Magomet Aliskhanov in Ingushetia, a province bordering Chechnya, was the latest in a series targeting top government officials in the mainly Muslim southern Russian region.
Interior Ministry spokesman Nazir Yevloyev said the attack happened around 12 p.m. (0800 GMT) in the region's largest city Nazran and officials were searching for the assailants.
Ingushetia's chief prosecutor blamed the attack on Chechen rebel warlord Shamil Basayev, who has taken responsibility from some of Russia's worst terrorist attacks.
Like other North Caucasus regions, Ingushetia has suffered frequent spillover violence from Chechnya, ravaged by separatist conflict for much of the past 12 years, as well as attacks by its own militants and criminal gangs.
Last month, a bomb killed the regional deputy interior minister and six other people. Last August, Prime Minister Ibragim Malsagov, the region's second-highest-ranking official, was wounded in a roadside bomb attack that killed a bodyguard and wounded two others. In April 2004, a car bomb targeted regional President Murat Zyazikov, the AP reports.
Analysts have expressed concern that major violence could break out in the North Caucasus even as the Kremlin asserts life is returning to normal in Chechnya, the AP reports.
Meanwhile, in Chechnya, a suspected rebel died when resisting arrest Wednesday, the regional Interior Ministry said. The incident happened at a gas station outside the capital Grozny when a police officer shot dead the alleged militant after coming under fire as he tried to detain him, the ministry said.