Terrorists who target innocent civilians must be "poisoned like rats," the Russian-backed leader of Chechnya wrote in a newspaper article Tuesday.
"We have always believed and we continue to believe that terrorists must be hunted down and found in their lairs, they must be poisoned like rats, they must be crushed and destroyed," Ramzan Kadyrov wrote in the Russian daily Izvestia, a day after suicide bombers struck a pair of Moscow subway stations in a deadly rush-hour attack.
"The struggle against terrorists must involve the toughest measures and defeating this evil with only persuasion and educational measures is impossible."
Russian investigators believe Chechen rebels may have been behind the deadly strike.
Moscow paused to mourn its dead Tuesday, and flags across the city were lowered to half-staff as hundreds of thousands of commuters returned to the transit system. Authorities said the attacks have killed at least 39 people - an increase of one since Monday - and wounded more than 60 others.
Television stations canceled entertainment programing for the day, while some also pulled commercials. After being closed most of the day, both stations reopened around 5 p.m. (9 a.m. ET) Monday, said Veronica Molskaya, a spokeswoman for the Russian Emergencies Ministry.
"Our preliminary assessment is that this act of terror was committed by a terrorist group from the North Caucasus region," said Alexander Bortnikov of the Federal Security Service, in reference to the investigation at one of the blast sites.
The Russia-Chechnya conflict dates back nearly 20 years, with Chechens having laid claim to land in the Caucasus Mountains region. Thousands have been killed and 500,000 Chechen people have been displaced by the fighting. Chechnya is located in the North Caucasus region of Russia between the Black and Caspian seas.