Two police officers and two soldiers have been killed in a gun battle with militants in the southern Russian republic of Chechnya, officials say.
They were ambushed in the Vedenskiy district late on Tuesday by up to 15 gunmen, who later fled, they added. Six other security personnel were injured.
Later, a court bailiff and a relative were killed in neighbouring Ingushetia.
Violence in the North Caucasus since Saturday has left 10 security personnel and 23 militants dead, officials say.
Overnight on Monday, a policeman was killed and six others injured by a bomb explosion in the Chechen capital, Grozny, while three militants and a soldier were shot dead during a gun battle in Dagestan, authorities in the two republics said.
Earlier, gunmen ambushed a Dagestani police patrol, reportedly killing two officers. A sniper shot dead a third officer in a separate incident.
The latest clashes come after a string of successful attacks by militants on high-level government targets in the North Caucasus.
Last month, the president of Ingushetia, Yunus-Bek Yevkurov, was critically injured by a car bomb in an apparent assassination attempt.
Two weeks earlier, Dagestan's interior minister was shot dead.
Russian forces have fought two wars against Islamist separatists in the mainly Muslim republic of Chechnya since 1994. The conflicts claimed more than 100,000 lives and left it in ruins.
Chechnya has in recent years been more peaceful, but the fighting has spread to Dagestan and Ingushetia, where correspondents say a violent Islamist insurgency is growing.
In April, President Dmitry Medvedev ordered the end of a decade-long "counter-terrorism operation" in Chechnya, which was supposed to pave the way for the withdrawal of thousands of federal troops.
But the BBC's Rupert Wingfield-Hayes in Moscow says that the violence of the past five days shows that despite government claims, the insurgency in the North Caucasus is far from being defeated.