A suicide bomber detonated a truck packed with explosives at a local police headquarters in Russia's Ingushetia region on Monday killing at least 19 people and wounding 68 others.
The bombing was the latest in a series of attacks against police and politicians in Russia's mainly Muslim North Caucasus region that authorities have blamed on Islamist insurgents, undermining the Kremlin's control of its southern flank.
Russian President Dmitry Medvedev ordered his interior minister to take additional measures to ensure security in the region, which borders Chechnya.
The truck bomb exploded at the gate of the police base in Ingushetia's biggest town of Nazran as officers lined up at the start of their working day, the region's deputy interior ministry Zyaudin Dourbekov told Reuters.
"The suicide bomber drove the Gazel truck to the building and detonated the device," Dourbekov said. He said at least 19 people had been killed and another 68 were wounded.
Thick smoke billowed from the burning building as fire-fighters fought flames near the mangled gate of the compound. ITAR-TASS quoted an unidentified investigator as saying the bomb was the equivalent of half a tonne of TNT.
"The bomb could be heard throughout the city," said resident Timur Akiyev.
A 38-year-old Nazran resident who identified himself only as Ilyas said he was considering moving his business to neighboring Chechnya as he felt the situation there was safer.
Police moved to increase security at other buildings in the city, said Kaloi Akhilgov, a spokesman for the region's president.
Ingush President Yunus-Bek Yevkurov was badly injured in June when a suicide bomber attacked his car. He is now recovering after intensive medical treatment and is expected to return to work soon.
Critics say flourishing corruption and abuse of power by authorities are the main reasons behind tensions. Yevkurov, a former paratrooper installed by the Kremlin to restore order, has vowed to fight both rebels and corrupt officials.