A tanker truck carrying 7,100 gallons of diesel fuel was taken at gunpoint from a city gas station early Friday, authorities said.

Authorities were searching for the truck. The case is being investigated as a robbery and there is no suspected connection to terrorism, police said.

The driver of the tanker was fueling the tractor-trailer about 5 a.m. when a man in a blue jumpsuit confronted him with a semiautomatic handgun, police spokesman Clifford Sterling said.

He forced the driver out of the truck and took off.

The tanker was last seen heading toward Interstate-95, but officials were unsure whether the red-and-silver tractor trailer was heading north or south. Both the truck and the tank were clearly marked with Baltimore Tank Lines logos.