The FTSE 100 fell 0.4% and the FTSE 250 shed 0.7% following news that Iran has hit back in response to the killing of a top Iranian commander by the United States last week.
Anglo American led losses on the main board, dropping 2% after saying it was in advanced talks to buy fertilizer maker Sirius Minerals. Sirius' shares soared 39% to their highest level in nearly four months.NMC Health slumped 18% and Finablr 12% after major shareholders of the two firms sold stakes. Finablr's unit Travelex also separately confirmed it was hit by a software virus attack.