MOSCOW (Xinhua) -- Two separate car bombings in Russia's turbulent North Caucasus early Tuesday killed at least one person and injured 19 others, authorities said.

The first bombing, which occurred near the Dagestan regional capital, Makhachkala, wounded four police officers and one civilian, the RIA Novosti news agency reported.
In the second attack, also in Dagestan, a suicide bomber detonated a car at a police post, killing a passing customs officer and injuring 14 others, police said.
On Monday afternoon in neighboring republic of Chechnya, three police officers were wounded in a roadside bomb explosion near the Dai village in the Shatoysky district.
Meanwhile in another southern Russian republic of Ingushetia, part of a trunk gas pipeline stretching from Mozdok in North Ossetia to Tbilisi, the Georgian capital, exploded on early Tuesday, with no casualties or injuries reported.
Authorities said the cause of the blast in Ingushetia remains unknown but terrorism could not be ruled out.
In April, the Kremlin formally ended an anti-terrorist operation in Chechnya, which has experienced two bloody wars in the past 15 years.