In all, more than 60,000 people have been killed in the island's separatist campaign since 1972.
Updated Gotabaye Rajapakse, the most senior civil servant in the defence ministry and younger brother of President Mahinda Rajapakse, later showed photographers blood stains on the sleeve of his white shirt.
Police said at least one soldier died along with the bomber while 14 other people, most of them security personnel, were wounded.
The defence ministry secretary, who emerged without a scratch, was in an armed convoy en route to a security council meeting with the president at the official Temple Trees executive residence, a source at the president's office told AFP.
"The defence secretary was in the convoy, he was unhurt. He drove straight to Temple Trees and the first thing he did was to hug the president," said the source.
who asked not to be named.
Police said the suicide bomber rammed a three-wh