ISTANBUL, May 9 (Reuters) - Turkey has sent a team of eight experts to the border with Syria to test wounded victims of the country's civil war for traces of chemical and biological weapons, the state-run Anatolian news agency said on Thursday.

Turkey started testing blood samples last week from Syrian casualties brought over the border for treatment to determine whether they were victims of a chemical weapons attack.

The civil defence team, equipped with a specialist vehicle which can detect evidence of chemical, biological and nuclear substances, has been stationed at the Cilvegozu border gate near the town of Reyhanli, Anatolian said.

Syrian President Bashar al-Assad's forces and opposing rebels have accused each other of using chemical weapons.

Britain said on Thursday it believed it was "very likely" that the Syrian government had used chemical weapons, but that it had "no evidence to date" that the rebels had used them.

Washington has long said it views the use of chemical weapons in Syria as a "red line". But, wary of the false intelligence that was used to justify the 2003 war in Iraq, the United States says it wants proof before taking any action.