A prominent Kurdish lawyer gunned down in southeastern Turkey appeared to have been shot by a policeman who was firing on suspects fleeing the scene of an attack on fellow officers, a deputy from Turkey's pro-Kurdish opposition said.

Diyarbakir city chief prosecutor Ramazan Solmaz said prosecutors and police forensic teams working at the site of Tahir Elci's killing were forced to flee yesterday when militants opened fire and threw explosives at an armoured police vehicle.

Saturday's killing of Elci, a lawyer and human rights activist, and Monday's brief incident underlined tensions in the mostly Kurdish region that have grown since a ceasefire with Kurdistan Workers Party (PKK) militants collapsed in July.

Prime Minister Ahmet Davutoglu has said Elci may have been caught in the crossfire between police and the militants.

Meral Danis Bestas, a deputy for the pro-Kurdish Peoples' Democratic Party (HDP), sent an email to the interior minister after viewing a video of the incident which took place in a narrow street during a shootout between police and militants.

In the video, plain-clothes police standing near Elci are seen firing automatic pistols at gunmen fleeing the scene of the attack in Diyarbakir, the region's largest city.

"The footage shows a figure running in the direction of Tahir Elci and the police opening fire in the direction of that person," Bestas wrote. "A plain-clothes policeman dressed in brown is shown opening fire in the direction of Tahir Elci and then he looks as if to see whether the cameras are filming him."

"The autopsy report and the camera footage point to Elci dying as a result of a police bullet," Bestas said.

Shortly before Elci's killing, two police officers were shot dead after they stopped a "suspicious vehicle" in a nearby street in what Solmaz, the chief prosecutor, said was an attack by PKK militants.

President Tayyip Erdogan, who founded the governing AK Party, has vowed to destroy Kurdish militant fighters since a ceasefire collapsed in July, reigniting a conflict in which some 40,000 people have died since it began in 1984.

The HDP, which is represented in parliament and has called for an end to the violence, said Elci had complained of death threats.

"Tahir Elci...was the target of some deep structures which are known to have carried out unsolved killings and which today give open support to the AKP government," it said.

Unsolved political killings were frequent at the height of the conflict between the state and the PKK in the 1990s.