U.S. Secretary of State George P. Shultz narrowly escaped an assassination attempt Monday when a bomb exploded near his motorcade. A window of his wife's car was shattered, but she was not injured.

The bomb, which went off on the outskirts of the Bolivian capital as Shultz and his party were driving in from the airport, blew a hole in the road and scattered chunks of pavement over a wide area.The explosion occurred seconds after Shultz's car passed over the road but before all 15 cars in the motorcade had gone by. Shultz and his wife, Helena, were traveling in separate cars.

No injuries were reported in the explosion, which was seen by this reporter from a vantage point four or five cars behind Shultz.

There was no immediate claim of responsibility for the bombing. Bolivia has no major organized anti-government guerrilla movement. However, U.S. efforts to stem Bolivia's thriving cocaine trade have fueled anti-American sentiment.

After the blast, police immediately closed off the highway and climbed a nearby hill to search for the bombers. They found a wire which they said had denotated the bomb by remote control.

Shultz was riding in one of the first few cars of the motorcade. Riding in his car was Foreign Minister Guillermo Bedregal of Bolivia and U.S. Embassy charge d'affaires David Greenley. A police escort accompanied the motorcade.

The secretary of state had been scheduled to go the Sheraton Hotel in La Paz but instead was rushed directly to the U.S. Embassy.

Shultz has been secretary of state since 1982. He has traveled widely abroad during that time, but has never before been attacked.

In La Paz, Shultz was expected to praise the government's efforts in fighting cocaine production and smuggling.