At least six people were killed and over 35 others were injured when some unknown militants attacked Pakistan's Inter services Intelligence (ISI) in the country's southern district of Sukkur on Wednesday evening, local media and police said.

Masood Bangash, the deputy superintendent of police said that a suicide bomber rammed his explosive laden vehicle into the ISI building complex, constituting of a number of government offices in Sukkur, a main district in the country''s southern Sindh province.