By Scott Wilson
Washington Post Foreign Service

BOGOTA, Colombia, Dec. 1 –– Police in a violence-ridden Colombian town defused two bombs a few hours before a visit there Thursday by Sen. Paul D. Wellstone
(D-Minn.) and U.S. Ambassador Anne W. Patterson, authorities reported today.

A Colombian police colonel said the bombs might have been rigged for an assassination attempt, citing the arrest of a man said to belong to a leftist guerrilla group hostile
to U.S. military aid for the Colombian government. But other U.S. and Colombian officials said there was no proof the American visitors were the intended targets.

Wellstone and Patterson, who took up her post three months ago, traveled to Barrancabermeja, an oil-refining town 150 miles north of Bogota, as part of Wellstone's visit
to review anti-drug activities in Colombia. Leftist guerrillas and privately funded paramilitary groups have clashed regularly in and around the city, battling for control of a
lucrative drug trade that is the target of a new U.S. military aid package.

Jose Miguel Villar, a police colonel, told reporters today that two powerful, shrapnel-filled bombs were discovered near a route Wellstone and Patterson could have taken
from the airport to to a brief meeting with human rights advocates in what is perhaps Colombia's most dangerous city. The explosives were rigged to a detonator and
police said the man they found with the bombs was a suspected urban commando of the National Liberation Army, or ELN, Colombia's second-largest leftist militant
group.

Colombian authorities and the State Department said later that they could not say if the bombs were intended for Patterson and Wellstone, but the two U.S. officials
moved from the airport to the city center by helicopter. "Such explosive devices are frequently found in the area of Barrancabermeja, an area of extensive activity by
illegally armed groups in Colombia," the U.S. Embassy in Bogota said.

"We are aware of no indication, no evidence that these explosives were targeted against the ambassador or the senator," said Philip T. Reeker, a State Department
spokesman. Wellstone's office in Washington said he was on his way home tonight.

Wellstone's visit came as Colombian guerrillas, comprising perhaps 20,000 armed members, wage a violent campaign against the government's $7.5 billion anti-drug and
economic development program known as Plan Colombia. The United States is contributing $1.3 billion to the effort, the majority of it to help the army and national police
force eradicate drug crops protected and taxed by leftist guerrillas and their right-wing paramilitary rivals.

Across the country, particularly in strategic drug-producing crossroads such as Barrancabermeja, the armed groups have concentrated their numbers and increased their
strikes against civilian and military targets in recent weeks. But the situation is most serious in the south, where Colombia's largest guerrilla group, the Revolutionary
Armed Forces of Colombia, or FARC, has paralyzed much of the country's richest coca region.

Both the FARC and the ELN, although they are rivals who operate independently, say their tactics are prompted by a U.S. military package that they say threatens
Colombia's independence and could broaden the long civil war.

While the assassination of senior U.S. officials might weaken American support of aid to Colombia, Wellstone would make an odd choice for a target. A liberal member
of the Senate Foreign Relations Committee, Wellstone was part of a small minority that opposed the aid package, arguing that much of the money should be spent on
programs to reduce domestic drug consumption.

He has also argued that the United States should not provide military aid to the Colombian armed forces because of their poor human rights record, a charge made
repeatedly by the leftist groups. In August, Wellstone criticized President Clinton's decision to waive human rights restrictions on the U.S. aid package, saying it "gives
the green light to the Colombian military to continue business as usual."

Staff writer Karen DeYoung in Washington contributed to this report.