NAZRAN — A suicide bomber exploded a truck at a police station in Russia's restive North Caucasus region on Monday, killing at least 20 people and wounding 68 others, officials said.

The bombing was the deadliest for months in Russia's south and dented the Kremlin's claims that it is stabilizing the North Caucasus region, where 15 years of separatist fighting in Chechnya has increasingly spilled into surrounding provinces.

The attacker rammed the gates of the local police headquarters in the city of Nazran in Ingushetia and detonated his explosives as police officers lined up for a morning check, said Kaloi Akhilgov, a spokesman for the regional president.

At least 20 people were killed and more than 100 were wounded, said Svetlana Gorbakova of the regional branch of the Investigative Committee of the Russian Prosecutor General's office. She said there were at least nine children among the wounded.

The attacker and the truck, which carried at least 20 kilograms of explosives, were pulverized by the blast, Gorbakova said. The police building was still on fire hours after the blast, and nearby buildings were badly damaged.

An Associated Press reporter saw 11 badly burned bodies at a morgue in Nazran, the largest city in Ingushetia, which borders Chechnya to the west.

While large-scale fighting from the two wars that have ravaged Chechnya since 1994 has ended, Islamic militants continue to mount regular hit-and-run attacks and skirmishes. Bloodshed has surged in recent months and increasingly spilled into Chechnya's neighbors.

Ingushetia's Kremlin-appointed president, Yunus-Bek Yevkurov, was badly wounded in a suicide bombing in June and hasn't yet returned to his duties. In a statement issued through his spokesman, Yevkurov said Monday's suicide attack had been organized by militants trying to avenge recent security sweeps in the forests along the mountainous border between Chechnya and Ingushetia.

"It was an attempt to destabilize the situation and sow panic," Yevkurov said.

Speaking in an interview with Russian News Service radio, Yevkurov blamed Chechen separatist warlord Doku Umarov for staging June's suicide attack on his convoy. He said law enforcement had tracked down the perpetrators of the attack and pledged that they will hunt down Umarov and other rebel warlords.

Since coming to power, Yevkurov has moved to end abuses against civilians by security forces — actions that contrasted sharply with the repressive rule of his predecessor, former KGB officer Murat Zyazikov. Rights groups say arbitrary arrests, torture and killings by security forces under Zyazikov had helped swell the ranks of rebels in Ingushetia, one of Russia's poorest regions.