Lorenzana said about 500 militants, including foreign fighters, joined the siege of Marawi, a mosque-studded city that is the heartland of the Islamic faith in the southern Philippines.
Seven other soldiers were wounded on Wednesday when two air force SF-260 close air support planes dropped bombs on a target in the heart of Marawi City, Defence Secretary Delfin Lorenzana told a news conference.
A Philippine military Marchetti S-211 jet bombed a tactical position in the southern city of Marawi, overrun with Islamic terrorists belonging to Abu Sayyaf and the Maute group - indigenous jihadist movements that have pledged allegiance to Islamic State caliph Abu Bakr al-Baghdadi - on Wednesday.
One of these include tactical air strikes and contrary to what the United States military would present in their press conferences covered around the world, it is anything but "surgical", at least to those troops in the ground who make it possible for the Air Force to successfully carry out their bombing runs.
Lorenzana said airstrikes may be curtailed because of the friendly fire incident, but military spokesman Padilla insisted the soldiers' deaths would not weaken the resolve of the armed forces.
"Indeed there was planning that was involved even prior to our entry to arrest Hapilon...when we got information he was holed up in the area", said Philippine military spokesman Brigadier-General Restituto Padilla.
As battles rage in Marawi against ISIL-linked fighters, misdirected strikes kill 10 soldiers, defence minister says.
Lorenzana said the military might suspend air strikes, describing the rebels as a small force that "cannot hold that long". He said Hapilon was still hiding somewhere in the city and that authorities were working to confirm whether another top militant had been killed.
As of Thursday, the crisis has claimed almost 180 lives: 36 soldiers and policemen, 120 Maute members, including foreign fighters, and 19 civilians.
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Fighting between government forces and the militants erupted on May 23. Eight others were foreign fighters, including a Chechen, a Yemeni and several Malaysians and Indonesians, Lorenzana said.
Ano also told AP that the extremists plotted to set Marawi ablaze and kill as many Christians in nearby Iligan city on Ramadan to mimic the violence seen by the world in Syria and Iraq.
The government's latest count added that 43,733 families or 218,665 individuals already moved out of Marawi and are now staying either in evacuation centers or with their relatives in nearby towns, cities, and provinces.
Duterte has vowed to drive out the radicals from the city by all means necessary, and to halt the spread of radical Islam in Asia's largest Catholic-majority nation.
Marawi Bishop Edwin de la Pena confirmed that it was Suganob in the video.
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"It's very sad to be hitting our own troops", Lorenzana said.
"If I think you should die, you will die".
President Duterte declared martial law in the south through mid-July, but lawmakers on Tuesday asked for a public session of Congress to determine whether it is still necessary.