Tony Blair surprised pupils at a Bradford school yesterday as he chatted to them during a lightning visit.

But a tired-looking Prime Minister, pictured at Tong School, had no time for the waiting media, as news was being relayed to him of the terrorist alert which closed Gatwick Airport when a man was found with a live grenade in his luggage after arriving on a British Airways flight from Venezuela.

Basketball players at Tong and Yorkshire Martyrs secondary schools were amazed as Mr Blair arrived in a dark green Jaguar at 4.30pm amid heavy security.

They had been expecting a visitor, but were not given details until they began playing on the courts at Tong School, Westgate Hill.

Arriving late from Sheffield, Mr Blair chatted for a couple of minutes to the shivering young players at a break in their play.

He remarked how tall Leeds Tigers player Joseph Davids, 16, was at 6ft 5ins.

And he shook hands with Curtis Latouche, 13.

"We didn't believe it would be the Prime Minister at first," he said, "He told us that our game looked good."

Mr Blair, wearing a navy suit and light blue shirt, was ushered into an hour-long private meeting with school staff which was also attended by officials including West Yorkshire Chief Constable Colin Cramp-horn and Bradford Council chief executive Ian Stewart.

Bradford South Labour MP Gerry Sutcliffe, who is chairman of governors at Tong School, said Mr Blair's visit was because the school and Yorkshire Martyrs shared status as the country's largest sports college.

Students' achievements in their GCSE exams doubled last year compared to 2001 and a major investment programme resulted in a new classroom block and improved sports facilities.

Proud head teacher Lyn O'Reilly said the school was only told about Mr Blair's visit 24 hours before.

"We all welcomed the investment but are concerned about target setting and bureaucracy," she said.

"Mr Blair was positive about taking those messages back. The clear message was that investment here will continue."

Five pupils at Tong School and Yorkshire Martyrs head boy and girl Zabir Moghal and Lydia Jarockyj met Mr Blair, where they discussed their future ambitions.

When one expressed an interest in being a journalist, he reportedly scowled and promised "a quiet word"!

As Mr Blair left hurriedly, watched by a group of pupils and teachers, Yorkshire Martyrs pupil Simon Phillips, 15, shouted: "Is there going to be a war in Iraq?"

But he, like the gathered press pack, was unable to get a response.