Sri Lanka’s president outlaws two Islamist groups suspected to be behind the suicide bombings on churches and hotels while the wife and child of the suspected ringleader are wounded during a military raid in safe house, his family and police say.

Sri Lanka’s police chief has refused a request by President Maithripala Sirisena to step down following suicide bombings on churches and hotels, two sources at the president's office say, deepening the rift at top levels of government.