San Vicente Del Caguan, Colombia ? Colombian paratroopers and counterinsurgency forces stormed rebel territory Friday, launching an offensive to reconquer an area twice the size of New Jersey after a 3-year-old peace process failed.

Hundreds of soldiers recaptured an old army base outside the main rebel town of San Vicente Del Caguan on the zone’s western fringe, raising the Colombian flag and singing the national anthem.

U.S.-made Black Hawk helicopters ferrying the troops came under rebel fire. Three soldiers were wounded and three choppers were hit, Armed Forces chief Gen. Fernando Tapias said.

As many as 5,000 guerrillas were believed to be inside the zone but most of the top rebel commanders have left the area, he said. Colombia mobilized 13,000 troops for the operation.

Elsewhere in Colombia, FARC rebels struck down an electricity tower, attacked a power plant and damaged a natural gas pipeline.

Toward the east, 1,000 soldiers moved on towns in a bid to re-establish government authority over a swath of southern Colombia given to the rebels in November 1998 to get them to end a war now in its 38th year.

President Andres Pastrana canceled the peace talks when guerrillas hijacked a civilian airliner Wednesday.