Death toll of the twin terror attacks in Volgograd has risen to 34, regional authorities said Tuesday.

"Eighteen people were killed by the explosion at the railway station, and 16 people died in the trolleybus blast," local health authorities told reporters.

On Sunday, a suicide bombing ripped a railway station in Volgograd. Another bomb went off Monday morning in a trolley bus in the same city.

Seventy people have been hospitalized with injuries, and 15 of them were rushed to Moscow clinics.

Federal and regional authorities have paid insurance to the injured people and to the families of those killed. Over 100 million rubles (3 million U.S. dollars) has already been transferred to Volgograd for that purpose.

According to the National Union of Insurers, the total amount to be paid by private insurance companies will exceed 50 million rubles (about 1.5 million U.S. dollars).

Funerals of the victims of the terror attacks were held in Volgograd amid tight security measures, with 5,200 police and interior troops as well as 1,100 volunteers patrolling the streets of the southern Russian city, regional government said in a statement.

Authorities have declared a five-day mourning in the region.