Yattoo, who hailed from Budgam district of central Kashmir, had a long association with Hizbul Mujahideen and was responsible for keeping alive the prolonged unrest of 2016 following the killing of group's commander Burhan Wani in an encounter with security forces on July 8.
The search operation was launched in Heff village in the Zainapora area, an army official said.
This is the third major encounter in Shopian in four days.
A fierce encounter is on between terrorists and security forces in south Kashmir's Shopian district
Puran Krishan was attacked near his residence in the Chowdhary Gund area of south Kashmir district, they said, adding that doctors declared Krishan brought dead after he was shifted to Shopian hospital.
The separatist Hurriyat Conference is finished in Jammu and Kashmir but attempts are being made to keep it alive from Pakistan, Director General of Police Dilbag Singh said on Monday, adding that the militancy in the region is "on crutches".
Relatives of the three youths, belonging to Dhar Sakri village in Kotranka of Rajouri area in Poonch, had lodged a written missing persons report in the local police station after they lost contact with them on July 17. The three were working as labourers in apple and walnut orchards in Amshipura.
The terrorists carried out the attack in Shirmal village in desperation as fruit transportation has picked up in the Valley.
The officials said the slain terrorists were affiliated with proscribed Jaish-e-Mohammad.
The three youths, Mohammad Imtiyaz and Ibrar Ahmed, residents of Kathuni mohalla of Dharsakri village of Rajouri, and Mohammad Ibrar, a resident of Tarkassi village of Rajouri, had left their homes on the pretext of working as labourers in Shopian and went out of contact with their families on July 17.
After a Kashmiri Pandit shopkeeper was shot at by terrorists in Shopian in Jammu and Kashmir on Monday, his family received immense support from his Muslim neighbours who not only rushed him to a hospital but camped at his house as well to ward off any further trouble.
Curfew continued for third day on Tuesday in parts of Shopian district in south Kashmir following killing of four persons in a firing incident on Saturday, the police said.
He accused the Apni Party, led by former People's Democratic Party leader Altaf Bukhari, and the union territory administration of using coercive tactics to buy loyalties of newly elected DDC members.
An elected sarpanch of the ruling National Conference was shot dead by suspected militants at his residence in Jammu and Kashmir's Shopian district ahead of assembly polls.
Heavy rains lashed parts of Jammu and Kashmir on Wednesday, triggering flash floods and landslides that blocked the strategic Jammu-Srinagar national highway with hundreds of vehicles stranded, and prompted authorities to shut schools in Doda, Kishtwar and Ramban districts.
Two army troopers were injured when militants opened fire on the security forces during a cordon and search operation in south Kashmir Shopian district on Tuesday evening.
Two terrorists were killed in an overnight gunfight in Hajin area of Bandipora district, officials said.
Constable Javaid Ahmad was found dead by the roadside at Sehpora in the neighbouring Kulgam district
The army said on Friday it has completed the Summary of Evidence against two of its men involved in July's Amshipura encounter in Shopian district.
The National Investigation Agency has arrested four terror associates during searches at 18 locations in Jammu and Kashmir following the registration of a case to unearth a conspiracy hatched by various terror groups to carry out attacks in the Union territory and other major cities, including New Delhi, an official said on Wednesday.
'The government of India must deliberate, for how long the police personnel will be sacrificed in such a manner. This is a big issue which must be resolved for the sake of the people of Jammu and Kashmir'
Two militants of Hizbul Mujaheedin outfit were killed in over 30-hour-long fierce gunfight in south Kashmir Shopian district on Wednesday evening.
The gunned-down terrorists have been identified as Abid Wagay, a resident of Rawalpora Shopian, and Shahjahan Mir, hailing of Amshepora Shopian, a police spokesman said.
Eight persons were injured in a powerful hand grenade blast outside a mosque in south Kashmir's Shopian district on Thursday morning.
'I have received Rs 5 lakh from the Jammu and Kashmir administration. Is that the price of my innocent son and others killed in cold blood'
Four Lashkar-e-Tayiba (LeT) terrorists were killed in an encounter with security forces on Monday in Shopian district of Jammu and Kashmir, police said.
Three Al-Badr terrorists were killed while one surrendered before security forces in an encounter in Shopian district of Jammu and Kashmir on Thursday, the police said.
'They were planning collection of arms dropped by drones and supply to active terrorists of Jaish-e-Mohammed in Kashmir valley; planting a vehicle-based IED in Jammu before 15th August and reconnaissance of important targets in other parts of the country'
A top militant commander of the terror group Hizbul Mujaheedin outfit was killed in a fierce gunfight in south Kashmir's Shopian district on Sunday.
Curfew remained in force for the second day on Monday in parts of Shopian district in south Kashmir following killing of four persons in a firing incident on Saturday.
Two militants were killed while an army major and a trooper were wounded in a ongoing fierce encounter in south Kashmir's Shopian district.
He was stopped by the administration and will be sent back by a flight later in the afternoon, the Congress leaders said.
Ishfaq Dar alias Abu Akram, was not only responsible for attacks on security forces, but also for civilian killings, police said.
The Army has launched an investigation into the incident, they added.
The case was registered under sections 302 (murder) and 307 (attempt to murder), the officials said.
One paramilitary Central Reserve Police Force trooper was killed and another wounded in a militant attack in south Kashmir's Shopian district on Monday evening.
Terrorists had abducted and later killed Nadeem Manzoor, a resident of Safanagri area, on Thursday night.
Two officers -- Lt Colonel Mukesh Jha and Major Amardeep Singh -- are among the five injured army personnel.
This is second attack on security forces in Srinagar -- the summer capital of Jammu and Kashmir -- within 24 hours.
On a specific input, the security forces launched a cordon and search operation in Reban area of south Kashmir district, a police spokesperson said.