police arrested 30 people and seized 21 small planes that were ferrying cocaine to Central America, officials announced Friday.

 In a joint U.S.-Colombian operation against a major trafficker, police arrested 30 people and seized 21 small planes that were ferrying cocaine to Central America, officials announced Friday.

Officials also announced a $2.7 million reward for the Colombian trafficker Daniel "Loco" Barrera. They said he was supplying Mexico's Sinaloa cartel, which ships the cocaine to the United States.

The suspects, who were arrested in Colombia early Friday, were mostly pilots and air traffic controllers, said Colombia's chief prosecutor, Viviane Morales.

Several of the suspects were in their 50s and 60s and had piloted cocaine flights for the late Medellin cartel kingpin Pablo Escobar, authorities said.

Investigators said most of the planes were seized this past week in Guatemala and Honduras, which have become key transit points for Mexican drug cartels due to extremely weak or nonexistant state control.

Barrera's organization was smuggling at least 10 tons of cocaine a month by plane to Central America, said Colombia's police director, Gen. Oscar Naranjo.

The suspects were wanted for extradition on U.S. indictments handed up in Miami, whose U.S. attorney, Wifredo Ferrer, attended the news conference along with President Juan Manuel Santos.

U.S. and Colombian authorities said they had been tracking drug flights for months into Central America but have little chance of making arrests there because security forces in Guatemala and Honduras are either weak or compromised by organized crime.

"I would say that general aviation (small planes) as a popular mode of drug trafficking has come back into fashion in the past five years," the regional head of the U.S. Drug Enforcement Administration, Jay Bergman, told The Associated Press.

That's partly because interdiction of cocaine-smuggling semi-submersibles on the high seas has been so successful, he added.

Such maritime interdiction encouraged traffickers to build their first fully submersible submarines, two of which have been seized, and to increasingly turn to small planes.

"They've filled the cocaine pipeline to Central America, which is causing a lot of problems," Bergman said.