Suspected militants sped through a checkpoint in Pakistan's capital of Islamabad on Friday and blew themselves up as police gave pursuit, killing one officer and injuring several others.

"Our initial information says that there was a man and a woman in the car," Islamabad operations police chief, Sohail Zafar, told reporters. The car did not stop at the checkpoint when police tried to halt it, he said.

"As they chased it, the people inside the car blew it up. It was a suicide blast."

Four police and two civilians were injured, he said.

The car was packed with explosives and headed for a high-value target in the capital, the interior ministry said in a statement, giving no further details.

"Had the car reached its target, it would have caused heavy losses," Interior Minister Rana Sanaullah told Geo News TV.

"Law enforcement's timely intervention averted a bloodbath," Prime Minister Shehbaz Sharif said in a statement.

The bombing took place near police headquarters on a main road that leads to government buildings housing the country's parliament and high offices.

Pakistani Taliban claimed the car bombing, saying it was revenge for the killing of one of their leaders.

"We take responsibility for the suicide attack against the enemy of Islam," said a statement from the militants known as Tehreek-e-Taliban Pakistan (TTP), an umbrella group of Sunni Islamist and sectarian groups.

TTP has ramped up attacks after last month calling off a ceasefire that was brokered by the Afghan Taliban in May.

The bombing came two days after a Pakistani military operation killed 25 TTP militants after a standoff at a counter-terrorism facility.

TTP militants have been waging a campaign of bombings and suicide attacks for over a decade to overthrow the government and run the country under a harsh brand of Islamic law.