ISLAMABAD: Pakistan PM Nawaz Sharif has stressed winning the fight against terrorism, a day after more than 70 people died in a suicide attack in Lahore.
At a meeting of security officials, Sharif said the nation's resolve to deal with militants was strengthening.
A number of arrests were made and weapons seized in five raids by security forces, the army said.
Taliban splinter group Jamaat-ul-Ahrar said it carried out the attack against Christians celebrating Easter.
At least 300 people were injured, with officials saying they expected the death toll to rise.
The area was more crowded than usual, as members of Lahore's minority Christian community had gathered to celebrate Easter at a funfair in the park.
However, most of those who died in the attack were Muslims.
At least one funeral, of 11-year-old Christian boy Sahil Pervez, was held on Monday.
The bombing of the amusement park in Lahore on Easter Sunday was the bloodiest on Christians in Pakistan since the 2013 Peshawar church bombing that killed more than 80 people.
But many believe there may be a wider context to the latest attack - 27 March was the deadline set by an alliance of more than 30 religious groups for the provincial government of Punjab to withdraw a new women's rights law they oppose.
And supporters of Mumtaz Qadri, a police guard executed last month for the 2011 killing of a provincial governor who advocated reform of the blasphemy laws, have also launched protests. They brought forward the customary 40th day mourning for Qadri by 13 days to coincide with 27 March and several thousand have now occupied a high-security zone in Islamabad to press demands which include the implementation of Sharia law.
Sunday's carnage in Lahore was claimed by Jamaat-ul-Ahrar, an increasingly effective faction of the Pakistani Taliban which has carried out several attacks in the north-western Peshawar valley region during the last few months.
Sharif visited some of the injured in hospital.At the later security meeting, he said defeating terrorism was imperative.
"Our resolve as a nation and as a government is getting stronger and the cowardly enemy is trying for soft targets," he said.
Sharif added that intelligence-based operations against militants should be speeded up.
"Terrorists have assassinated my children, sons and daughters in this war and God willing we will wipe them from this country," he said.
Meanwhile army spokesman Gen Asim Bajwa tweeted that security forces had carried out raids in Lahore, Multan and Faisalabad.
A "number of suspect terrorists and facilitators" were arrested and a "huge cache of arms and ammunition" seized, he added.
Meanwhile Facebook has apologised after a programme glitch resulted in users around the world being sent a notification to let friends know they were safe after the attack, meant only for subscribers in the Lahore area.
Facebook had been criticised in the past for deploying the Safety Check application more readily if Westerners are the likely victims.
'Message to Sharif'
The government of Punjab, of which Lahore is the capital, declared a state of emergency in the city and three days of mourning. Other regions declared one day.
Schools and markets in the province were closed on Monday.
Lahore is one of Pakistan's most liberal and wealthy cities. It is Sharif's political powerbase and has seen relatively few terror attacks in recent years.
A spokesman for Jamaat-ul-Ahrar, Ehsanullah Ehsan, said the group wanted to send a message to Sharif that they "have entered Lahore", and threatened further attacks.
Jamaat-ul-Ahrar is a breakaway group from Tehrik-e Taliban Pakistan. It has carried out several other attacks on Pakistani civilians and security forces in recent months.
The explosion, believed to have been carried out by one suicide bomber, hit the main gate to the Gulshan-e-Iqbal park in the early evening, a short distance from the children's playground.
Officials said the device had been packed with ball bearings.
There were scenes of anguish as parents searched for children amid the debris.
Pakistan has suffered regular incidents of Taliban-related violence, sectarian strife and criminal gang activity.
Estimated to make up about 1.6% of the population, they are the second largest minority in Pakistan after Hindus
Large population in Karachi but also in the Punjab heartland and the cities of Lahore and Faisalabad, and Khyber Pakhtunkhwa province particularly in Peshawar city.
Majority are descendants of low-caste Hindus who converted under the British Raj
Most remain poor menial workers, though there are wealthier Christians who came from Goa and are mainly in Karachi
Attacks, including church and hospital bomb blasts and mob attacks on Christian villages, have increased in recent years; the deadliest involved two bombs at a Peshawar church in 2013 which left around 80 dead