Explosions hit pipelines running through southern Russia early Sunday, cutting the supply of natural gas to the Caucasus countries of Georgia and Armenia during a cold snap.

Russia's NTV showed footage of twisted and smoking pipelines in a high mountain pass in North Ossetia. Overnight temperatures in Tbilisi plunged to minus 14, and by afternoon, much of the capital was without gas.

An explosion also hit an electricity transmission tower west of North Ossetia, interrupting electricity supplies to Georgia, said Sergei Petrov, a duty officer at Russia's Emergency Situation Ministry. He said the cause of the explosion near the city of Cherkessk, was not yet known.

"The situation is very difficult. We have enough gas for just one day," Georgia Energy Ministry spokeswoman Teona Doliashvili told The Associated Press.

It was not immediately clear whether the pipeline and power line explosions were connected, Russia's Emergency Situations Ministry said. Spokesman Viktor Beltsov initially said the pipeline blasts appeared to be accidental, but Nikolai Shepel, chief prosecutor for Russia's southern region, said a criminal investigation had been opened on charges of sabotage.

In recent years, explosions have damaged pipelines in Russia's turbulent North Caucasus region in blasts investigators have ruled sabotage. Criminal groups as well as militants with ties to Chechnya's separatist rebels have been suspected.

Georgian officials headed to neighboring Azerbaijan to negotiate getting gas through a pipeline between the Azerbaijani capital, Baku, and the Georgian port of Batumi. The RIA-Novosti news agency reported Georgia had started bringing in gas from Azerbaijan.

Georgian President Mikhail Saakashvili angrily called on Russia to do more to explain the cutoff and restore supplies and honor its "contract as is provided for under civilized, international trade relations," he said.

"Everyone should understand that Georgia is prepared for partnership and friendly relations but I don't advise anyone to speak to any country with threats or blackmail," he told reporters.

Russian gas goes across Georgia to Armenia, which sends back some electricity to Georgia. Electricity supplies also were cut in Armenia.

Shushan Sardarian, a spokeswoman for Armenia's gas distributor, told the AP that officials had tapped the country's emergency gas reserves and urged Armenians to cut back on electricity usage.

Neither Georgia nor Armenia produce significant amounts of gas, and they rely on Russia for the overwhelming majority of their supplies.

Armenia hopes to reduce its dependence on Russia by building a pipeline to bring gas from Iran, but the first section is not expected to be completed until 2007.