Miami (ANTARA News/AFP) - Police in the US state of Florida said Wednesday they had arrested a 17-year-old for plotting a bombing attack on his former high school to kill some 30 students and rival the 1999 Columbine massacre.

"We were probably able to thwart a potentially catastrophic event the likes of which the city of Tampa has not seen and hopefully never will," local police chief Jane Castor told reporters.

Jared Cano, 17, who had been expelled over a year ago for an off-campus incident, had planned to set off several homemade pipe bombs on the first day of school next week and target two administrators, authorities said.

Police, acting on a tip-off, searched Cano`s home on Tuesday, where they found a detailed "manifesto" with a minute-by-minute account of the plot, including layout drawings of where he would plant the bombs.

The materials also "mentioned his desire to cause more casualties than were suffered at Columbine," Castor said, referring to the school attack in which two well-armed teenagers killed more than a dozen people.

Police found several bomb components including fuel, shrapnel, plastic tubing, fuses and timing devices in his room, she added.

They also uncovered a marijuana-growing operation, with lights, plants, a scale and a blue glass pipe, the St. Petersburg Times reported.

There were no guns in the house, but Cano had previously been arrested on charges of stealing a firearm and possession of marijuana, said Police Major John Newman, who added that authorities were "very, very familiar with him."

Administrators at Tampa`s Freedom High School said Cano had been expelled a year and a half ago and that his presence at the school would have attracted attention, making it unlikely the plot would succeed.

"I`m not sure his plot was realistic to carry out," principal Chris Farkas said at a news conference held at the school.

Castor declined to comment on Cano`s psychological state, saying "we`re not in the business of diagnosing the mental health of individuals."

The arrest was the latest to evoke the April 20, 1999 attack on Columbine High School in Colorado, in which two heavily-armed students killed 13 people and wounded 23 others before turning their guns on themselves.

At his first court appearance, when the judge asked Cano if he would like to say anything, he responded: "The plan wasn`t..." before his public defender cut him off, according to the St. Petersburg Times.

"Don`t say anything," it quoted the attorney as saying.

"I can talk... I`m allowed to say what I want," Cano replied.

The public defender then whispered in the teen`s ear, before saying: "He has no comment."

Cano was due back in court on September 5. (*)