A little-known militant group has taken responsibility for the attack
Children of foreign staff working for the United Nations in the Pakistani capital, Islamabad, will have to leave the country.
The move is part of new UN security measures following last month's massive suicide bomb on the Marriott hotel that killed more than 50 people.
The UN says the measure will have no impact on its operations. The UK announced a similar move on Wednesday.
The US says militants are threatening the existence of Pakistan as a state.
Meanwhile, at least four people have been killed in a suicide bomb attack in the north-west of the country.
The decision to move dependents of UN international staff out of the country "has been approved" by UN Secretary General Ban Ki-moon, UN information officer Ishrat Rizvi told the Reuters news agency.
"It's a matter of only evacuating the children of international staff members which doesn't make any difference to the work of the United Nations," Ms Rizvi said.
Correspondents say there is growing unease about security in Islamabad after the attack on the Marriott, the city's most prestigious hotel.
British Airways has suspended its six flights a week there indefinitely.
The UK Foreign Office said on Wednesday that 60 children would be affected by its decision to move dependents of British staff out of the country.
Canada, Australia, the US, the Netherlands and Denmark all have a no-dependents policy.
A little-known militant group, the Fidayeen-e-Islam, says it carried out the Marriott attack to stop American interference in Pakistan.
The week, Gen David Petraeus, who was recently promoted to be head of the US Central Command, said militants were "a threat to Pakistan's very existence".
In the latest violence at least four people were killed in a suicide attack on a house owned by a member of the governing party in North West Frontier Province, police say.
The politician, Asfandya Wali Khan of the Awami National Party, was not hurt.
"The bomber shouted 'God is great!' and ran toward Asfandyar Wali Khan. I saw a police guard open fire and hit him in the head," police officer officer Riaz Khan told the AP news agency.
"He fell down and blew himself up."
The government has said that it is determined to defeat militancy following the explosion.
"We have two options: either hand over the country to the Taleban or defeat them," Interior Ministry chief Rehman Malik said.
"We will defeat and eliminate them."