Turkey will not let a delegation of pro-Kurdish MPs enter the city of Cizre in southeastern Turkey, the interior minister said Thursday, despite fears of a humanitarian crisis caused by a week-long military curfew there.

"We will not allow them (the Peoples' Democratic Party - HDP delegation) to go to Cizre," Interior Minister Selami Altinok told reporters in Ankara. "It is our duty to protect them."

The government says it has launched a military operation in Cizre and imposed the curfew to eliminate Kurdistan Workers Party (PKK) militants after a string of attacks in Turkey.

Anltinok said 30-32 members of the PKK had been killed by the armed forces in the Cizre military operation.

He said that 800 kilogrammes of explosives had been destroyed, 10 suspected PKK members arrested and caches of arms seized.

He added that one civilian had been killed in clashes.

The HDP however says that 21 civilians, including children, have been killed in the operation and a humanitarian crisis is worsening by the day.

HDP co-chairman Selahattin Demirtas has been leading fellow deputies and dozens of supporters on a march to Cizre to end the curfew and draw attention to the plight of its 120,000 residents.

But the security forces Thursday blocked their foot march outside the town of Idil west of Cizre, still a few dozen kilometres from the city, the party and Turkish media said.

Altinok said that the curfew, which is now in its seventh day, would be continued so long as required and insisted it was in line with the law.

"Once our activities (the military operation) have been completed as soon as possible, we want to lift the curfew."

Pro-Kurdish media quoted HDP Mardin deputy Mehmet Ali Aslan who is currently trapped in Cizre as saying at least 8 civilians were killed attacks by Turkish forces overnight.

"It is not possible to go out and buy bread, water is coming to an end and there is no electricity," the HDP quoted Demirtas as saying Thursday on the road to the city.

"In Cizre, 120,000 people have been held hostage by the state for a week," he added.

He said that the corpses of young girls and boys caught in the crossfire could not even be buried.

"They put ice on the corpses to stop them putrefying. Because burials are banned."