Story highlights The Pakistan Taliban has claimed responsibility for the incident

Islamabad (CNN) Four military personnel and two civilians were killed Wednesday when a suicide bomber struck the Pakistani city of Lahore, according to a government spokesman.

The assailants targeted members of the security services who were carrying out the national census -- Pakistan's first in 20 years -- said Malik Muhammad Ahmed Khan, a spokesman for the state government of Punjab.

Another two people are in critical condition, he said.

Prime Minister Nawaz Sharif issued a statement expressing his condolences to the victims.

The Pakistan Taliban, whose objective is to establish Sharia law in Pakistan, claimed responsibility for the bombing, spokesman Mohammed Khurrassani said in a phone call with CNN.

Read More