Tiger Woods had to back off his opening tee shot in the first round of the 137th British Open on Thursday when a wayward swallow swooped into his line of sight. It was the only distraction that seemed to bother him on the Old Course at St. Andrews as he ran off a stretch of seven birdies on nine holes and seemed to pick up exactly where he left off the last time he played this course in 2000, when he won by eight shots.

Almost as astounding as his 6-under 66, good for a one-shot lead over Australian Mark Hensby, was Woods's revelation after the round that his mother, Kultida, had been on vacation in London during last week's terrorist bombings, apparently staying in a hotel across the street from one of the four blasts. Woods said she never told him and that he still didn't know which bombing site she'd been near. He indicated he wasn't informed about it until Wednesday. "I've talked to her, but she hasn't really said a whole lot," Woods said. "Typical mom, you know. You know my mom. 'Are you okay?' 'Yeah, good. What are you going to do on the course?' She likes to change the subject real fast. I didn't know. She didn't tell me. . . . That's kind of how our family is. . . . You just deal with life and move on."

Play was halted for two minutes of silence Thursday, just as most of Europe honored the victims of the July 7 bombings in London that killed 53 and injured 700.

Woods was just off the 14th green when an air horn sounded, signaling the stoppage in play. He took off his hat and stood with his head bowed and his hands behind his back, and later was asked about his thoughts.

"For me personally, I was more thankful than anything else because my mom was in the building right across the street from where the bomb blew up," he said. "I was very thankful that my mom is still here. It very easily could have been very tragic for me personally. I can only imagine what everyone else who was involved, where they lost a loved one or had loved ones hurt, what they might have been going through."

Woods was playing golf in Ireland most of last week. Asked why she hadn't mentioned it to him, he smiled and said: "We don't do that in our family. When my dad had [stomach] cancer, he didn't say anything. When I had my knee surgery [two years ago], I didn't say anything. We just do that. It's one of our deals of probably being a Woods, I guess. Kind of deal with things and move on. She's here, so everything is good to go."

Kultida Woods, who was on the grounds watching her son play, could not be reached for comment. Mark Steinberg, Woods's longtime agent, said Woods had not even been aware his mother was in London last week. He indicated he had not yet spoken to Kultida Woods but said he was "pretty sure" she would not comment about her whereabouts last week and her proximity to the bombings.

Famous for his ability to focus whenever he steps on a golf course, Woods certainly seemed comfortable under overcast skies and stiff breezes off the North Sea. His 66 was a shot better than his opening-round 67 here in 2000, when he won with a major championship-record 19-under 269. Woods is trying to join Jack Nicklaus as only the second player to secure every major at least twice.

Nicklaus, playing in what he has said will be his final major, saw his name go to the top of the leader board at 8 a.m. when he birdied the 376-yard first hole with a six-foot putt. But three straight bogeys early on his back nine led to a 3-over 75, the same total as playing partner Tom Watson.

Several highly ranked players struggled in the afternoon, when winds kicked up and heavy rain fell shortly after 6 p.m. Ernie Els, No. 3 in the rankings, bogeyed three of his first four back-nine holes and shot 74. So did No. 4 Phil Mickelson after a triple bogey at the 456-yard 15th. Jim Furyk, No. 8, had two front-nine double bogeys and ended at 78.

U.S. Open champion Michael Campbell of New Zealand played in the morning and had a 69. Vijay Singh, No. 2 in the world, birdied the final hole and managed to stay close to the lead with a 69.

Woods started his morning with three straight pars before his round began to take off on the 480-yard No. 4, when he hit a wedge to within 20 feet and made the birdie putt. "I've been playing well and it's a continuation of it," Woods said. "My last three events I've really played well so I'm just trying to build on that. For me, it's nothing that I haven't done in the last three events. . . . I still feel very comfortable out there."

Tiger Woods, who won at St. Andrews in 2000, works the sixth fairway en route to a 1-stroke lead after one round.