LONDON: A powerful bomb blast shattered windows and wounded at least 22 people at an office complex in southeastern London's Docklands. The massive explosion sent police and emergency workers racing to the scene only one hour after an Irish news service received a statement announcing that the 17-month cease fire between the IRA and the British Government was over. Intelligence analysts are confused, since the bomb attack comes at a time when the IRA talks with the British government have been progressing smoothly. British Prime Minister John Major issued a statement calling upon Sinn Fein to condemn the bombing and reaffirm its commitment to the peace process. TIME's London Bureau Chief Barry Hillenbrand reports: "No one really knows who the bombers are, but the bomb was a complete shock to many in the IRA's leadership, and could jeopardize the talks. There are still a lot of people who want them to continue, but this will make it much more difficult." It is possible that an IRA splinter group is trying to call a halt to the negotiations, but the sheer scale of the operation implies that a large efficient group did the job. Hillenbrand calls the operation "a very professional, very clean job. The bombers could be very high up the IRA chain of command."