who was arrested?
Browne and Arnett.
Arrest and interrogation
Later on during the day of the altercation, the police collected Browne and Arnett from the AP bureau in Saigon and took the pair to what they described as a "safe house". The police interrogators said that they would be arrested but were unspecific about the charges. 
what is the double seven day scuffle? A physical altercation on July 7, 1963. between who? The secret police of Ngô Đình Nhu—the brother of President Ngô Đình Diệm—and a group of US journalists.
Arnett and his colleague, the Pulitzer Prize-winning journalist and photographer Malcolm Browne Peter Arnett and Malcolm Browne Browne and Arnett
Double Seven Day scuffle Double Seven Day scuffle Double Seven Day scuffle
Introduction Introduction Arrest and interrogation
uch taller than Nhu's men, counterattacked and caused the secret police to retreat. Arnett and his colleague, the Pulitzer Prize-winning journalist and photographer Malcolm Browne, were later accosted by policemen at their office and taken away for questioning on suspicion of attacking policemen. Peter Arnett of the Associated Press (AP) was punched on the nose, and the quarrel quickly ended after David Halberstam of "The New York Times", being much taller than Nhu's men, counterattacked and caused the secret police to retreat. Arnett and his colleague, the Pulitzer Prize-winning journalist and photographer Malcolm Browne, were later accosted by policemen at their office and taken away for questioning on suspicion of attacking policemen. Browne and Arnett 
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Double Seven Day scuffle [SEP] Arrest and interrogation
Later on during the day of the altercation, the police collected Browne and Arnett from the AP bureau in Saigon and took the pair to what they described as a "safe house". The police interrogators said that they would be arrested but were unspecific about the charges. One charge was that of assaulting two police officers, but the interrogators hinted that more serious offences such as organising illegal demonstrations were being considered. The officers conversed among themselves in French, a language which the reporters did not speak, but Arnett thought that they mentioned the word "espionage". After four hours of questioning, the pair were charged with assault.