Nothing was taken and no one was home Friday during the midday break-in that detectives witnessed by chance in the Hancock Park neighbourhood of Los Angeles, sheriff's Capt. Mike Parker said.
The fighter was informed of the burglary and will proceed to his training base in the northern resort city of Baguio to prepare for his third fight against Juan Manuel Marquez of Mexico on Nov. 12 in Las Vegas, his attorney and chief of staff Franklin Gacal said.
Gacal said the break-in occurred when a security guard who oversees the house had gone out to eat.
"Manny is happy that nothing was stolen," Gacal said.
The area is patrolled by the Los Angeles Police Department, but detectives from the Sheriff's Department were in the area on an unrelated criminal investigation when they saw the home being burglarized and made the arrests, Parker said.
The four people were being questioned. Their names have not been released and they have yet to be charged.
Pacquiao, 32, has won 14 straight fights and is considered by many the best pound-for-pound boxer in the world and among the greatest of all time. He is a megastar in the Philippines, where he is also a singer, actor and congressman.
Associated Press writer Oliver Teves in Manila contributed to this report.