MOSCOW — Russians today mourned the 39 people killed in a dual suicide attack on Moscow's subway system by lighting candles and leaving carnations at one of the sites, and officials called for a return of the death penalty to punish terrorists.

Monday's attacks shocked a country that had grown accustomed to such violence being confined to a restive southern corner — and marked the return of terrorism to the everyday lives of Muscovites after a six-year break.

Many have speculated the blasts — blamed on Muslim extremists in the Caucasus region, which includes Chechnya — were retaliation for the recent killing of separatist leaders in the area by Russian police.

Some lawmakers today called for the return of capital punishment for convicted terrorists, and President Dmitry Medvedev in televised remarks called on judges to consider amending terrorism laws.

The city remained on edge, even as people began to commute on the subway again.

"I feel the tension on the metro. Nobody's smiling or laughing," said university student Alina Tsaritova.

The preliminary investigation found that female suicide bombers detonated belts of explosives during the Monday morning rush-hour at the stations.

By The Associated Press