NAZRAN, Russia: A suicide bomber rammed a truckload of explosives into the local police headquarters in Russia's Ingushetia region yesterday killing 20 people, the deadliest attack in the North Caucasus region since 2005.

A wave of attacks against police and politicians blamed on Islamist insurgents in the mainly Muslim North Caucasus are undermining the Kremlin's control of its southern flank.

A yellow truck exploded at the gates of the main police station in Nazran, Ingushetia's largest city, as police officers lined up at the start of their day.