The United Nations has raised its security level in Pakistan, ordering the children of U.N. employees out of the country.

U.N. officials Thursday said dependent children of staff will no longer be allowed to live with their parents in Pakistan.

The measure comes as security deteriorates in the country. More than 50 people were killed last month during a massive truck bombing at the Marriott Hotel in the capital, Islamabad.

On Wednesday, British officials announced that about 60 children of British diplomats would return home from Pakistan.

In other news, Pakistani officials say at least four people were killed in a suicide bombing targeting a politician. The bombing happened Thursday in the northwestern town of Charsadda, at a guest house belonging to Asfandyar Wali Khan, head of the Awami National Party. Khan was not hurt in the attack.

The Awami National Party is a secular party supporting the rights of ethnic Pashtuns based in Pakistan's northwest. The party is part of the ruling coalition and is sharply critical of Taliban militants.

The head of Pakistan's interior ministry, Rehman Malik, and Afghan President Hamid Karzai condemned today's attack. In a statement, Mr. Karzai said the aim of such attacks is to weaken the Pashtuns inside Pakistan.

Elsewhere, in the northwest, Pakistani security officials say troops killed at least 25 militants today in the Bajaur tribal region. The military has been carrying out an operation to rid the area of al-Qaida and Taliban militants for several weeks.

Some information for this report was provided by AFP, AP and Reuters.