Ilkley Grammar School was forced to close one of its main building and abandon lessons yesterday as hundreds of pupils staged a peace demonstration and walkout.

Around 400 Year 9 to Year 13 pupils from the upper school building spilled into the town centre to oppose the looming war with Iraq as police were called to try to dispel the crowds.

The protest began around 8am with a small throng of students demonstrating outside the school.

But following morning registration at 8.45am, hundreds of pupils put down pen and paper to line both sides of the road outside Ilkley Grammar School.

Countless dozens held anti-war placards, banners and notes - some hastily scribbled on school notepads - encouraging passing motorists to honk their horn in support.

And with the majority of passers-by obliging, the sound of anti-war songs, cheers and car horns filled the air outside the school.

Then at mid-morning the students marched to the town centre to peacefully invade the pedestrian crossing at the junction of Brook Street and The Grove.

While a number congregated there, more than 250 pupils marched to Ilkley Grammar's lower school building - which houses the Year 7 and 8 pupils- to try to gain their support.

However, teachers concerned for the safety of the younger pupils did not allow them to join the demonstration. The rest of the marchers then rejoined those left in the town centre to continue the protest.

Head teacher Gillian James said "I regret this course of action. This was not a school agreed protest and we did not sanction this or condone it in any way.

"Many of the youngsters were good-natured and it was a good-natured protest by and large but a few pupils let us down. Some of the Year 11 pupils were just intent on disrupting things but we have names and we will be looking into that."

By 1pm in the afternoon, police had moved all the protesters away from the town centre and lessons continued at the lower school site as normal.

However, the upper school building remained closed for the day although Mrs James was keen to stress it would reopen today.

She said: "I'm expecting a normal day on Thursday although I will be taking this matter up in assemblies during the day.

"To be frank, I've never seen anything like this before. We have worked very, very hard to make this a good school and we don't want the school's reputation to be damaged.

"From speaking with some of the pupils beforehand, it was not the intention to come down into Ilkley at all. That was never supposed to be an issue.

"All that was expected was a protest on the roadside outside the school but the presence of the television cameras seemed to cause this.

"We do regret that and I am concerned for the name of the school. Anyone who wants to ring me or come and see me can do so."

But many pupils defended their right to protest claiming that although their actions would not stop war, their voices would at least have been heard.

Seventeen-year-old sixth