A one-day spike in attempted suicides in Novosibirsk this week has left local health officials scratching their heads.

A total of 15 people tried to kill themselves over a 24-hour period Sunday and Monday in the Siberian city, Tamara Savicheva, deputy head of the Novosibirsk Emergency Medical Service, said by telephone Tuesday.

"Most of them were people of working age. We managed to save them," Savicheva said, adding that all of them had been hospitalized and are in stable condition.

There was no discernible pattern to be found in the one-day wave of suicide attempts, Savicheva said. "All of them used different methods: Some took drugs, others slit their veins and one person tried to hang himself," she said.

On Saturday, eight people attempted suicide in the city, which has a population of 1.4 million and usually sees an average of three to four suicide attempts over every 24-hour period, Savicheva said.

Savicheva said it was unclear if the jump in suicides was merely an anomaly or was driven by some specific factor.

Russia has the second-highest suicide rate in the world, after Lithuania, according to the World Health Organization. Suicides claim between 57,000 and 60,000 lives in the country annually, according to figures from the Serbsky National Research Center for Social and Forensic Psychiatry, a leading social and psychiatric research center.

Around 90 percent of suicides stem from psychological disorders, but in times of economic turmoil suicide rates usually skyrocket, said Boris Polozhy, a top psychologist with the Serbsky center.