BOGOTA, COLOMBIA, NOV. 8 -- Suspected members of the Medellin cocaine cartel have kidnapped two more journalists, both members of prominent families, in what authorities say is an effort to increase their leverage in pressing for an amnesty and an end to extradition.

Eight armed men in two vehicles intercepted that of prize-winning TV journalist Maruja Pachon and her sister-in-law and press assistant Beatriz Villamizar, at about 7:30 p.m. Wednesday, dragging the women from the car and killing the driver. The attack raised the number of kidnapped journalists to nine.

No one took immediate responsibility for the attack, but traffickers, calling themselves the Extraditables, have acknowledged holding the other seven journalists.

"There are strong suspicions, because of the modus operandi and the targets, that it was the work of the same people as before," said a senior government official. "That is, a sector of the Medellin cartel."

Pachon is the sister-in-law of slain presidential candidate Luis Carlos Galan, and is married to Alberto Villamizar, a prominent Liberal Party congressman. In September she was named by President Cesar Gaviria to head a state-run movie company after years in television news.

Galan, a Liberal and an outspoken opponent of the traffickers, was gunned down by the Extraditables on Aug. 18, 1989.

Guido Parra, a lawyer representing the Extraditables, said last week that the traffickers would surrender if they were pardoned and extradition was banned. The proposal was primarily aimed at influencing a constitutional assembly that is to be elected in December, with the power to ban extradition and declare an amnesty.

Law enforcement officials said today the new kidnappings appeared to be aimed at putting direct pressure on Gaviria by abducting someone close to the Galan family. Gaviria was Galan's campaign manager and entered the presidential race after Galan was assassinated.

Gaviria has said repeatedly he would not negotiate with the traffickers under any circumstances.

The Extraditables are already holding Francisco Santos, a member of an influential Liberal family and news editor of El Tiempo, the nation's largest newspaper, and Diana Turbay, daughter of former Liberal president Julio Cesar Turbay.

"I do not believe the government is negotiating," said a knowledgeable Western diplomat. "But when you are holding members of families like the Santoses, the Turbays and now touching the Galans, the pressure is there and it is great."

The new kidnappings came amid an unprecedented flurry of public letters exchanged among the Extraditables, intermediaries for the kidnapped journalists and a group of prominent citizens seeking a solution not only to the abductions but to drug trafficking and its attendant terrorism.

The almost daily round of statements and responses, with each group repeatedly praising the others' desire for peace and a prompt resolution of the crisis, has allowed the Extraditables to air their grievances against the state and frame the debate in terms of government violations of the traffickers' human rights.

The statements are faxed to the media and immediately made public.

"We have said our primary concern is no longer extradition, but the violation of human rights and the assassinations of our comrades," said a letter Tuesday from the Extraditables to Juan Gomez Martinez, a former mayor of Medellin who was named intermediary by the families of those abducted.

Minister of Interior Julio Cesar Sanchez said the government is allowing the public exchange on "humanitarian grounds" to help free the journalists, but the cordial tone and widespread publicity surrounding the traffickers' statements appear to have angered officials.