Armed men attacked police headquarters in Pakistan's port city of Karachi on Friday, officials said.
Three members of the security forces and a civilian were killed, government officials and Ghulam Nabi Memon, police chief for Sindh province, confirmed.
Three attackers also died, Sindh government spokesman Murtaza Wahab Siddiqui said.
“Four people were killed in the attack, including two policemen, one ranger and one sanitary worker,” Mr Siddiqui said.
“The operation has concluded with the killing of all three terrorists.”
The Pakistani Taliban claimed responsibility for the attack.
Speaking on Samaa TV, Interior Minister Rana Sanaullah called the attackers “terrorists … armed with grenades and other weapons” and said they had fired at a gate with a rocket.
Prime Minister Shehbaz Sharif vowed on Friday to stamp out the violence.
“Pakistan will not only uproot terrorism, but will kill the terrorists by bringing them to justice,” he tweeted.
“This great nation is determined to end this evil forever.”
Pakistan has witnessed a surge in militant attacks since November, when the Pakistani Taliban ended a months-long ceasefire with the government.
Pakistan's outlawed Tehrik-e-Taliban are a separate group but are allies of the Taliban in Afghanistan, which seized power there more than a year ago as US and Nato troops withdrew. The Taliban takeover in Afghanistan emboldened the Pakistani militants, whose top leaders and fighters are hiding across the border.
The Pakistani Taliban on Saturday warned of more attacks against the security forces.
"This attack is a message to all the anti-Islamic security agencies of Pakistan ... the army and police will be targeted at every important place until the way for implementation of the Islamic system in the country is paved," it said in an English-language statement.
