Investigators work at the site of a blast on a trolleybus in Volgograd December 30, 2013. A bomb blast ripped a trolleybus apart in Volgograd on Monday, killing 14 people in the second deadly attack in the southern city in two days and raising fears of further violence as Russia prepares to host the Winter Olympics. [Photo/Agencies]

LONDON - IOC President Thomas Bach expressed full confidence Monday that Russian authorities will deliver a "safe and secure" Olympics in Sochi despite the two deadly suicide bombings in southern Russia that heightened concerns about the terrorist threat to the Winter Games.

The International Olympic Committee said Bach wrote to Russian President Vladimir Putin to offer his condolences following the attacks on Sunday and Monday that killed more than 30 people in Volgograd.

A suicide bomber killed 14 people aboard an electric bus during Monday's morning rush hour, a day after a bomb blast killed at least 17 people at the city's main railway station.

"This is a despicable attack on innocent people and the entire Olympic Movement joins me in utterly condemning this cowardly act," Bach said in a statement. "Our thoughts are with the loved ones of the victims."

Volgograd is located about 650 kilometers (400 miles) northeast of Sochi, which will host the Olympics from February 7-23. Russia's first Winter Games are a matter of personal pride and prestige for Putin.

Russian authorities believe the two attacks were carried out by the same group. No one claimed responsibility for the bombings, which came several months after Chechen rebel leader Doku Umarov threatened new attacks against civilian targets in Russia, including the Olympics.

Bach said his letter to Putin expressed "our confidence in the Russian authorities to deliver safe and secure games in Sochi."

"I am certain that everything will be done to ensure the security of the athletes and all the participants of the Olympic Games," he said.

"Sadly terrorism is a global disease but it must never be allowed to triumph," Bach added. "The Olympic Games are about bringing people from all backgrounds and beliefs together to overcome our differences in a peaceful way."

Russian Olympic Committee chief Alexander Zhukov said there was no need to take any extra steps to secure Sochi in the wake of the Volgograd bombings because "everything necessary already has been done."