As the number of heavy bombers in the RAF increased, greater tonnage could be dropped on a target with fewer aircraft. Later mass RAF raids used between 400 and 700 four-engined bombers, and on some nights, Bomber Command could send two 400-bomber forces to separate targets. Operation Gomorrah in 1943 and the attack on Dresden in 1945 each used nearly 800 aircraft. Nearly 900 were sent to Berlin in February 1944; with aircraft on other missions that night more than 1,000 bombers were active, but 1,000 bombers were never sent against a single target after June 1942.