Religion of Peace working overtime in Russia.

MOSCOW — At least 14 people were killed and 28 injured Monday morning by a suspected suicide bomb attack on a crowded trolley bus in the Russian city of Volgograd — the second such attack on mass transit in the city in as many days.

Ten passengers were killed immediately from the blast and four more died on the way to and in hospitals, officials said.

Russian law enforcement agencies said the explosion was a terrorist act and that they suspect a connection between Monday’s attack and a suicide bombing on Sunday, less than 19 hours earlier, at the city’s main railway station.

No group claimed responsibility for either of the attacks, the latest of several to hit southern Russia in recent months. Volgograd is close to the troubled Caucasus region, where Chechen rebel leader Doku Umarov has vowed to use “maximum force” to prevent Russia from staging the Winter Olympics, which he called “satanic games held on the bones of our ancestors.”

Alexander Zhukov of the Russian Olympic Committee said in televised remarks that all necessary security measures have been taken to provide safety at the Olympic Games in February.

The death toll of the Sunday attack grew to 17, including the bomber, as a victim died overnight at a hospital, officials said.

“This is the second terrorist act in Volgograd over the two days, and investigators don’t rule out that they could be connected,” Vladimir Markin, spokesman for the Russian Investigative Committee, said in televised remarks. “Investigators are already questioning those passengers who survived the attack and whose condition allows them to talk with investigators.”