BELGRADE (Reuters) - Two people have died in freezing temperatures in northern Serbia, health authorities said on Sunday, and hundreds of people had to be rescued from vehicles after heavy snow and strong winds lashed the country over the weekend.

A pregnant woman tried to reach the maternity ward in the northern town of Zrenjanin but the ambulance got stuck in a column of cars halted by snow, the Beta news agency reported. Medical staff transferred her to a heated truck where she gave birth to a healthy baby girl and named her Snezana (Snow White).

"So far we have rescued 661 people including 30 children from passenger cars and buses, mainly in Vojvodina, but we are also having problems in the easternmost part of the country," Predrag Maric, the head of the Interior Ministry's emergencies department, told Reuters.

The Serbian authorities have imposed a state of emergency in several municipalities and banned heavy freight traffic throughout the country in a bid to keep the roads open.

Heavy snow also hit neighboring Croatia over the weekend. One person froze to death in the central town of Korenica, the Jatarnji List daily said on its website on Sunday, quoting police. Croatia's national automobile club warned drivers not to travel unless it was absolutely necessary.

(Reporting by Aleksandar Vasovic; Editing by Stephen Powell)