The kidnapped construction workers were freed on Saturday by Shining Path rebels who had abducted the men five days earlier from a town near the country's main natural gas fields.
Additional troops were sent to the district of Echarate on Monday to join the search for the police and pursue the rebels, Defense Minister Alberto Otarola said.
Peruvian officials have said two soldiers and two police officers were killed in the search operation, and 10 other soldiers were injured. A funeral was held in Lima on Monday for one of the police officers.
Peru's government sent a force of about 1,500 soldiers and police to search for the hostages last week. The government has said those killed included a police officer who was in a helicopter on Thursday when the aircraft was attacked with gunfire.
Peruvian officials have said the hostages were freed because that search operation put pressure on the rebels, and that there were no negotiations with the captors, which had initially demanded a $10 million ransom.
Officials have not confirmed details of how the two police officers went missing. But Dionisio Vilca, the father of one of the missing officers, said on Sunday that comrades who had been with the two told him the men had just been lowered from a helicopter when a gunbattle with rebels broke out.
The Peruvian workers were kidnapped on April 9 from hotels in the hamlet of Kepashiato, near the Camisea natural gas field. They were working as contractors on gas industry projects, and included employees of the Swedish construction company Skanska and the Peruvian company Construcciones Modulares.
Once freed, the men hiked out of the jungle on Saturday, reaching a small town.
The Shining Path, which is financed by the cocaine trade, is a small remnant of the Maoist rebel group that terrorized Peru in the 1980s and 1990s. It is believed to number about 300-500 fighters centered in the Ene and Apurimac Valley region where more than half of Peru's coca is grown. The town where the kidnapping occurred is in an adjacent region.
The rebels once before carried out a mass abduction in 2003, when they kidnapped 71 of workers of the Argentine company Techint who were laying a natural gas pipeline. Those hostages were freed two days later, and the government said no ransom was paid.