At least two police officers have died and 12 people, six of them police officers, been injured after a vehicle packed with explosives blew up while approaching a police patrol post near Dzhemikent, some 20 kilometers north of the coastal town of Derbent in southern Daghestan.
The remains of a person whom police tentatively identified as the driver of the vehicle were also found at the site of the explosion.
The Islamic State (IS) militant group has claimed responsibility for the February 15 attack.
It was the third violent incident in the area since the start of the year, following an attack on police in January and a shoot-out late on February 14 in the village of Khuchni, during which police freed a local teacher who had been abducted hours earlier by an unidentified armed group.
According to the news portal Caucasian Knot, Daghestan's security forces initially suspected the February 15 blast was the work of the "southern" group of militants, presumably meaning the group in question is one of those fighting under the banner of the so-called Caucasus Emirate (IK) proclaimed in 2007 by Chechen insurgency leader Doku Umarov
The IK has, however, been seriously weakened since Umarov's death in 2013 by the defection of many of its fighters, including two senior Daghestani commanders, to IS.
It is not even known for certain whether the IK has elected a new leader to succeed Magomed Suleymanov (aka Abu Usman Gimrinsky), the Avar from Daghestan who was killed in August 2015 after serving in that position for only a few months.
Umarov's brother Akhmad (aka Abu Khamza) distanced himself in October 2015 from video footage in which four masked men claiming to be Chechen fighters pledged allegiance to him as their leader.
By contrast, Daghestan's Interior Minister Colonel General Abdurashid Magomedov estimated in November that some 900 young men had left Daghestan to join the ranks of IS. Some journalists, however, claim the figure is closer to 5,000.
IS claimed responsibility for two attacks carried out in Daghestan last year, both in the south of the republic. First, it claimed to have opened fire on a group of police and security personnel in Mageramkent in late August.
Then four months later, it said its fighters were responsible for opening fire on a group of security personnel sightseeing at Derbent's Naryn-Kala fortress late on December 30, killing one of them and injuring 11 more.
Police sources recently claimed that groups of militants in Daghestan's western Tsumada district that borders on Chechnya and Georgia are aligned with IS. The overall commander of those fighters, Magomed Abdulkhalikov, was reported killed in a shoot-out with federal security personnel last month.
While the number of people killed in the North Caucasus in clashes between police and armed militants fell in 2015 for the fifth consecutive year, Daghestan as the largest of the North Caucasus republics again registered both the largest number of casualties (123 dead and 27 injured) and the largest number of armed clashes (57), including two designated as acts of terrorism.
How many of those attacks were the work of fighters who have sworn allegiance to IS is impossible to determine, given that IK and IS fighters in the Caucasus use the same tactics, and Daghestan's police and security organs appear reluctant to confirm IS involvement in attacks on their personnel, even if the group explicitly claims responsibility.