Gen. Athar Abbas, a military spokesman, corrected an earlier report that 30 people were killed, citing misinformation from sources on the scene, reported CNN.
Interior Ministry Secretary Kamal Shah told Reuters that 89 policemen were wounded during the siege. Four of the 10 or 12 gunmen were killed in the battle, and three were arrested. Other reports claim that the remaining attackers blew themselves up.
Officials said nearly 100 people were injured, according to the BBC.
Rescue workers are taking the wounded to local hospitals, where they are being screened to make sure no militants are hiding among them, said Shar.
The brazen attacked was the second in less than a month in the Lahore area; gunmen targeted a bus carrying members of the Sri Lankan national cricket to a match on March 10. At least eight members of the team were wounded and six Pakistani police officers were killed.
Islamist militants have launched a campaign of violence that threatens to destabilize the nation and its one-year-old civilian government.
President Barack Obama voiced support for President Asif Ali Zardari's government during an assessment of Afghanistan and Pakistan policies that was announced Friday.
Pakistani Interior ministry chief Rehman Malik rejected the idea that Pakistan is teetering on lawlessness, during an interview with Geo TV on Monday, reported Agence France Presse.
"It is wrong to say that law and order has collapsed in Pakistan. We are very near to (tracing) the attackers involved in this," said Malik, calling Monday's siege a "planned, organized, terrorist attack."
"This shows the extent to which the enemies of our country can go. We have to fight with unity. Hostile elements have to be eliminated with unity."
The police academy attackers gained entrance to the building by using grenades and then opening fire on officers performing their morning drills.
One of the suspects caught by the police, had a grenade and an Afghan passport, but witnesses said the attackers were speaking a dialect common to southern Punjab, an area close to the militant-heavy Afghan border areas.
A 20-year-old recruit told the New York Times that one of the attackers said shouted out: "We have come, oh attackers of the Red Mosque, we have come."
In July of 2007, militants staged an eight-day siege on the mosque in Islamabad, that ended when former-President Pervez Musharraf ordered the military to attack the mosque.