By Nick Butler

The bombing took place on a bus in Volgograd north of Sochi and is the largest bombing of its kind for almost three yearsOctober 23 - Russian authorities will be "up to the task" of maintaining security during the Winter Olympic Games in Sochi next year in the aftermath of a terrorist attack on the nearby city of Volgograd, it was claimed today.

At least six people were killed and a further 30 injured when a female suicide bomber struck on a public bus in the city shortly after 2pm on Monday (October 21).

It was the largest scale attack on the transport system in Russia for almost three years since a bomb blast killed 37 people at Moscow's Domodedovo airport in January 2011

This followed similarly destructive attacks on the Moscow subway the previous year.

Although their were less casualties on Monday than in those episodes the resumption of such attacks rises fears with the Games in Sochi lie just over three months away.

This is particularly because the Black Sea resort lies only 600 miles away from Volgograd and is close to Chechnya, where some extremists are fighting for independence from Russia. 

About 40 passengers were reportedly on the bus in Volgograd when the bomb went off on Monday afternoonAbout 40 passengers were reportedly on the bus in Volgograd when the bomb went off  in an attack which poses fresh questions for Russian security forces ahead of Sochi

The IOC claimed security is a "priority" ahead of the Games, before expressing confidence that enough is being done.

"Our condolences go to all those affected by the recent bombing in Volgograd," a spokesman told insidethegames.

"Unfortunately, terrorism is a global phenomenon and no region is exempt, which is why security at the Games is a top priority for the IOC.

"At the Olympics, security is the responsibility of the local authorities, and we have no doubt that the Russian authorities will be up to the task.

"The Games are a celebration of peace and we look forward to that spirit being respected in 2014."

Sochi lies only 600 miles away from Volgograd where Mondays bombing took placeSochi lies only 600 miles away from Volgograd where the bombing took place, and close to the volatile Chechnya and Dagestan regions

Security has been a big priority since Munich 1972 when 11 members of the Israeli Olympic team, who were taken hostage and eventually killed, along with a German police officer, by the Palestinian group Black September.

Some of the security plans for Sochi 2014 were revealed earlier this month.

These include "control zones in and around Sochi which will require tickets and ID", as well as "forbidden zones which will be accessible only to people and vehicles with some work-related connection to the area".

They will come into operation in January and remain in place until March so for the duration of both the Olympic and Paralympic Games.

Russian President Vladimir Putin has also agreed with US leader Barack Obama to pool some security resources ahead of the Games.

Similar agreements are being sought with other countries including the United Kingdom, which successfully survived security fears when holding the London Games last summer.

American and Russian leaders Barack Obama and Vladimir Putin have agreed to pool their resources ahead of Sochi 2014 to reduce security risksAmerican and Russian leaders Barack Obama and Vladimir Putin have agreed to pool their resources ahead of Sochi 2014 to reduce security risks

Seperatists in Chechnya region have fought two wars with Russian forces over the last two decades.

In recent years the violence has spread across the Northern Caucasus region, including mainly Muslim regions such as Ingushetia and Dagestan.

Although Sochi lies to the west of this area on the Black Sea coast, it is certainly close enough for there to be severe spillover. 

In July, Doku Umarov, leader of an Islamist insurgency in Chechnya, urged followers to use "maximum force" to prevent Sochi 2014 being staged.

Umarov is Russia's most wanted man and the leader of the group who claimed responsibility for the bombings on both the Moscow metro in 2010 and at Domodedovo airport in 2011.

No group has yet claimed responsibility for Monday's bombing, but the attacker is believed to be a 30-year-old women married to an Islamist extremist and explosives expert.

She also reportedly hailed from the same Dagestan region where the Boston Marathon bomber Tamerlan Tsarnev spent time before carrying out his attack in 2012.