Turkey's foreign minister said on Thursday that Turkish authorities were conducting blood tests on wounded Syrian refugees to assess whether their injuries had been caused by chemical weapons.

"We will keep on carrying out tests on each and every injured Syrian," who has fled to Turkey, Ahmet Davutoglu told reporters in Ankara.

The minister said more than a dozen test results "required further study and should be taken seriously" but did not elaborate further.

"The studies continue. We will publish the results once they are concluded," he said.

Prime Minister Recep Tayyip Erdogan will take several blood samples from Syrian refugees when he visits Washington on May 16, reported Turkish news channel NTV.

Following claims in recent months that chemical weapons have been deployed in Syria, Ankara took immediate steps to bring the issue to the attention of the international community, noted the minister.

The claims must be backed by concrete evidence, stressed Davutoglu.

Turkish authorities have set up a decontamination facility at a refugee camp in the border town of Sanliurfa as a "precautionary measure", Anatolia news agency reported.

The minister said the tests aimed to make sure "nobody would dare use chemical weapons" and that they had been carried out from the early days of the uprising.

Western nations have raised concerns about the use of chemical weapons in the escalating conflict between the regime of President Bashar al-Assad and rebels fighting to oust him.

Top UN rights investigator Carla del Ponte said Sunday that according to testimony, rebels may have been using the deadly nerve agent sarin.

Davutoglu said there was no evidence that Syrian rebels had used chemical weapons according to the information he received from the UN, warning against attempts to "legitimise the Syrian regime."

Ankara has sided with rebels fighting to topple Assad's regime, taken in around 400,000 refugees as well as army defectors and repeatedly called on the international community to act on the unfolding crisis.