MAKHACHKALA, Russia – President Dmitry Medvedev made a surprise visit Thursday to the violence-wracked southern province of Dagestan, telling police and security forces to use tougher, "more cruel" measures to fight the "scum" responsible for terrorist attacks.

Russian President Dmitry Medvedev, right, and officials observe a minute of silence for victims of this week's suicide bombings, in Mahachkala, the capital of Dagestan, a province in Russia's volatile North Caucasus, Thursday, April 1, 2010. [Agencies]

Russia's security chief said some terror suspects had been detained.

Twin suicide bombings in Moscow — which Islamic militants from the North Caucasus claim to have carried out — have refocused attention on the violence that for years has been confined to Russia's predominantly Muslim regions. The rush-hour attacks Monday on the Moscow subway killed 39 people and left nearly 90 hospitalized.

Medvedev on Thursday copied the style of Russia's powerful prime minister, Vladimir Putin, both in his dress — a black T-shirt under a black suit coat — and his rough language in ordering that much more be done to stop the attacks.

"The measures to fight terrorism should be expanded, they should be more effective, more harsh, more cruel, if you please," he told federal and local officials in a televised meeting.

Funerals were held Thursday at four Moscow cemeteries for some of the subway victims. At the Khovanskoye cemetery, the family, friends and colleagues of Anna Permyakova, a 34-year-old nurse, could not hold back tears as they placed flowers on her open casket. Permyakova had worked in a rehabilitation center and many of her former patients attended the funeral in wheelchairs.

Federal Security Service director Alexander Bortnikov, who joined Medvedev in Dagestan, said the organizers of the Moscow attacks have been identified as "bandits" from the Northern Caucasus and some had been detained. He did not give specific numbers.

"We know the personalities of organizers," Bortnikov said during the meeting. "We have detained a number of people, conducted interrogations, got evidence."

In recent months, police and security forces have killed at least two high-profile Islamic militants, but they have been unable to capture the veteran Chechen militant Doku Umarov, who has claimed responsibility for the Moscow subway attacks.

"We have torn off the heads of the most odious bandits, but clearly this was not enough. In any case, we will find them all and punish them," Medvedev said.

But the president also warned officials that they must avoid aggravating deeply ingrained prejudices.

"People who live here in the Caucasus are citizens of Russia, not people of Caucasus origin. It's not a foreign province, it's our country," he added.

Umarov, who leads Islamic militants in Chechnya and throughout the North Caucasus, said the Moscow subway bombings were revenge for the killing of civilians by Russian security forces.

"Any politician, any journalist who accuses me of terrorism only makes me laugh, causes me to grin. I have not heard anyone accuse Putin of terrorism for the murder of civilians who were killed on his orders," Umarov said in a video posted Wednesday on kavkazcenter.com, a Web site used by rebels.

Umarov seemed to be taunting Putin, who had just vowed to "drag out of the sewer" the terrorists who plotted the subway attacks.

Umarov, 45, fought Russian forces in both separatist wars in Chechnya of the past 15 years. Shortly after taking over the leadership of the rebel movement in 2006, he announced a change of tactics. Instead of struggling for Chechen independence, the militants would seek to create an Islamic state across the North Caucasus. Umarov declared himself the emir, or military leader, of a Caucasus Emirate. He is believed to receive financial support from al-Qaida.

"In many ways, our North Caucasus has followed the path of the Middle East and North Africa, where nationalism as opposition to the West has been replaced with an Islamism that denies the West altogether," said Sergei Markedonov of the Moscow-based Institute for Political and Military Analysis.

This policy, however, led to a split with other Chechen rebel leaders — including Akhmed Zakayev, who now lives in London — and it is unclear how much power Umarov wields over North Caucasus militants.

Zakayev on Thursday denounced the subway bombings as a "monstrous crime" and said that Umarov has "deprived himself of the right to make any political demands or talk about morals."

He added, however, that Umarov is a product of 15 years of fighting in Chechnya.

"Violence produces violence," Zakayev said in an interview with Associated Press Television News. "A huge state can't terrorize the population for 15 years without a backlash. People involved in that suffer a shift in their psychology."

Zakayev said that Umarov has the loyalty of his band of fighters but no broad public following in the Caucasus.

Vladimir Bobrovnikov, an independent expert on the North Caucasus, also described Umarov as a "marginal figure," who rose to power only after his more talented rivals were killed or fled the region.

The terrorist attacks in the North Caucasus are believed to be motivated not only by radical Islam but in some cases by a desire for personal revenge against police and security forces, who have been accused of killings, kidnappings and torture. The heavy-handed tactics have served to swell the ranks of Islamic militants.