Mr Choudhury's visit to the shrine had been widely publicised

Three people were killed in the blast and dozens injured, including the British High Commissioner in Bangladesh, Anwar Choudhury.

Mr Choudhury was treated for leg injuries but is not seriously hurt.

UK Foreign Secretary Jack Straw said he was "deeply shocked" by the bombing. It is unclear who carried out the attack.

Mr Choudhury told the AFP news agency from hospital in Sylhet: "The bomb hit my stomach after it was hurled, but did not explode [then].

"It fell on the ground near the foot of the district chief and then exploded with a big bang," he said.

This is a hell of a scene with dozens of injured lying in the emergency ward and in the corridors Eyewitness, Sylhet hospital Profile: Anwar Choudhury

The diplomat was later flown back to Dhaka for further treatment.

The chief government administrator of the district was among the injured, along with Mr Choudhury's bodyguard.

Britain's Foreign Office said it could not rule out that this was an assassination attempt on Mr Choudhury.

Bangladeshi Prime Minister Begum Khaleda Zia denounced the bombing and sent her sympathies to the high commissioner and the other victims.

A blast at the same shrine, of Muslim saint Hazrat Shahjalal, in January this year killed three people.

The latest explosion occurred as Mr Choudhury walked out of a mosque at the shrine after Friday prayers. Police say they suspect a bomb was thrown by somebody in the crowd.

Sympathies

The Bangladeshi-born Mr Choudhury only took up his post in the country last week.

His family is originally from the Sylhet region and his visit to the mosque was widely publicised.

Mr Straw sent his sympathies to the victims of the attack.

"Details of exactly what happened and the nature of the injuries are not clear. We are grateful for the support we are receiving from the Bangladeshi authorities," he said.

In the January attack, three people were killed by an explosion at the shrine during a religious gathering.