UPDATE - Perpetrators of E. Ghouta massacre to pay 'heavy price'

UPDATE WITH MORE REMARKS FROM ERDOGAN

By Muhammet Emin Avundukluoglu

ANKARA (AA) - Turkish President Recep Tayyip Erdogan said Tuesday the perpetrators of the latest chemical attack in Douma in Syria's Eastern Ghouta would pay "a heavy price".

"I curse those who committed this massacre," Erdogan told lawmakers of his Justice and Development (AK) Party in the parliament.

"Those who committed this massacre will definitely pay a heavy price," said Erdogan.

"We are conducting talks, [and] efforts over this. I had a phone conversation with Mr. [Russian President Vladimir] Putin yesterday. Talks will continue today and tomorrow," said Erdogan.

Bashar al-Assad regime forces struck targets in the Damascus suburb’s Douma district on Saturday midnight using a poisonous gas, which left at least 78 civilians dead, according to the White Helmets, a local civil defense agency.

- Operation in Afrin

Erdogan said that a total of 4,071 terrorists have been "neutralized" since the start of the Operation Olive Branch in Syria's Afrin region.

"The number of terrorists neutralized in Afrin as of this morning is 4,071. In northern Iraq, 337 [PKK] terrorists have been neutralized," Erdogan said.

"Our fight [against terrorism] will continue until the last terrorist is eliminated," he added.

Turkey launched Operation Olive Branch on Jan. 20 to clear YPG/PKK and Daesh terrorist groups from Afrin amid growing threats from the region. On March 18, Turkish-backed troops liberated Afrin town center, which had been a major hideout for the YPG/PKK since 2012.

According to the Turkish General Staff, Operation Olive Branch was aimed at establishing security and stability along Turkey's borders and the region as well as protecting Syrians from terrorist cruelty and oppression.

In his remarks, the president also criticized demonstrations organized in YPG/PKK terror group in European countries, saying that Europe has become a "playground for terrorists".

"We are tired and disgusted at confrontation with terrorists in the mountains and streets of Europe," said Erdogan.

The PKK -- listed as a terrorist organization by Turkey, the U.S. and the EU -- waged a terror campaign against Turkey for more than 30 years and has been responsible for the death of nearly 40,000 people.

More than 1,200 Turkish security personnel and civilians, including a number of women and children, have been killed since July 2015 alone when the group resumed its armed campaign against the country.