SAN DIEGO -- The Department of Homeland Security will fill seven cross-border tunnels, including a nearly half-mile long tunnel that extends from San Diego to Tijuana, it was reported Wednesday.

The decision to fill the tunnels comes after the Los Angeles Times in January reported that the tunnels had not been filled, largely because of jurisdictional issues and a lack of money.

"We have the funding and are moving forward," said Michael Friel, a spokesman for Customs and Border Protection, the agency responsible for detecting and filling in tunnels, according to The Times.

The $2.74-million project is targeted for completion by mid-May, Friel told The Times Tuesday.

The tunnels include two between Calexico and Mexicali, as well as the longest tunnel ever discovered between Mexico and the United States, a passage nearly a half-mile long connecting warehouses in San Diego and Tijuana.

Another tunnel, which has remained unfilled for 13 years, is known as the "Taj Mahal" because of its lighting system and reinforced concrete walls, the newspaper reported.

Because of increasing enforcement above ground, smugglers have been going underground to ferry drugs and people into the United States. In the last few years, authorities have discovered nearly 50 tunnels, most of them with a terminus in California or Arizona, The Times reported.

Authorities have tried to seal the larger tunnels, plugging them with concrete at the exit points and at the border, but leaving the areas in between largely intact. At least two tunnels - one with an exit in Nogales, Ariz., and the other with an exit in San Diego -- were reused by smugglers who dug around the cap to access the original passage.