The blasts at hotels and churches have so far killed at least 359 people
One of the nine bombers that detonated explosives in Sri Lanka on Easter Sunday was a woman, deputy defence minister Ruwan Wijewardene told reporters on Wednesday.
The blasts at hotels and churches have so far killed at least 359 people, the deadliest such event in south Asia's history.
Sri Lankan police said on Wednesday they had detained 18 more people for questioning over the Easter Sunday attacks on churches and hotels, claimed by the Islamic State group, as the death toll climbed again to 359.
The extremist Islamic State group made its claim after Sri Lankan officials said the suicide bombings in Sri Lanka were carried out in retaliation for attacks on two mosques in New Zealand that killed 50 people in March.
Police spokesman Ruwan Gunasekera said the death toll had risen to 359 from 321 overnight, with about 500 people wounded, but did not give a breakdown of casualties from the three churches and four hotels hit by the bombers.
Islamic State said through its AMAQ news agency the assaults in Sri Lanka were carried out by seven attackers but gave no evidence to support its claim of responsibility. If true, it would be one of the worst attacks carried out by the group outside Iraq and Syria.