Operation Sovereign Borders, Australia’s hard-line strategy to stop illegal boat arrivals, is on track for its busiest year since it was launched in 2013, with people smugglers changing how they operate by using smaller boats carrying fewer people.

At least 10 boats containing up to 183 people in total were intercepted between the start of the financial year to the end of April, according to data published by the Department of Home Affairs. There may be an 11th, but the reports are not clear about the origins of a small group of people transferred to regional processing on Nauru in February.