(CNN) -- U.S. authorities say they have discovered another extensive drug tunnel that stretches from a home in Tijuana, Mexico, to San Diego, California.
The half-mile tunnel, discovered Thursday morning in a warehouse in the Otay Mesa area of San Diego, is close to a similar one federal agents found earlier this month, the U.S. Immigration and Customs Enforcement agency said.
In that case, authorities also seized about 30 tons of marijuana in what federal agents say is one of the largest marijuana seizures in U.S. history.
Agents have made several arrests in connection with Thursday's tunnel discovery, said Virginia Kice, a spokeswoman for the customs agency.
Federal agents with the San Diego Tunnel Task Force also seized an undetermined amount of marijuana from a tractor-trailer in the area and have found more of the drug in the tunnel, Kice said.
Authorities said they will release more details about the incident at a news conference Friday afternoon.