UPDATE 2-U.S. says reports of killing of Kurdish politician in northeast Syria 'extremely troubling'

(Adds more comments from the State Department, background, U.S.
threats of sanctions)

By Humeyra Pamuk

WASHINGTON, Oct 13 (Reuters) - The United States is looking
into reports that a Kurdish politician and captured Kurdish
fighters were killed in northeastern Syria amid Turkey's
offensive, a State Department spokesman told Reuters on Sunday,
adding that Washington found the reports disturbing.

On Saturday, the Syrian Observatory for Human Rights, a
UK-based organization which reports on the war, said
Turkey-backed groups had killed nine civilians, including Hervin
Khalaf, secretary general of the Future Syria Party.
"We have seen reports of the killing of (Hervin) Khalaf....as
well as several captured SDF fighters, the latter having been
apparently shot while in the hands of Turkish Supported Armed
Syrian Opposition elements," a State Department spokesman said,
referring to Turkey-backed rebels.

"We find these reports to be extremely troubling, reflecting
the overall destabilization of northeast Syria since the
commencement of hostilities on Tuesday," the spokesman said in
an email.

Khalaf had been returning from a meeting in Hasaka at the
time of the attack in which her driver and an aide were also
killed, said Hussein Omar, the Future Syria Party's coordinator
in Europe. Party officials including Khalaf have had contacts
with U.S. officials since it was founded in 2018, he said.

Asked about the accusation that Turkey-backed groups had
killed Khalaf, the spokesman for the Turkey-backed National
Army, which groups Syrian rebel factions, on Saturday said they
had not made it as far as that area.

"We condemn in the strongest of terms any mistreatment and
extrajudicial execution of civilians or prisoners, and are
looking further into these circumstances," the U.S. State
Department spokesman said.

Ankara launched the cross-border assault against the YPG
militia on Wednesday after U.S. President Donald Trump withdrew
some U.S. troops from the border region, opening of the biggest
new fronts in years in an eight-year old civil war that has
drawn in global powers.

Turkey says the YPG is a terrorist group aligned with
Kurdish militants in Turkey and that it reserves the right to
protect its borders.

Turkey's incursion has raised international alarm over its
mass displacement of civilians and the possibility of Islamic
State militants escaping from Kurdish prisons. The Kurdish-led
forces have been key allies for the United States in eliminating
the jihadist group from northern Syria.

Trump's administration has threatened Turkey with economic
sanctions over potential targeting of civilians and has warned
it not to allow any Islamic State militants to escape.

Senior State Department official last week said Ankara
should avoid any "disproportionate and inhumane" actions in
northeast Syria, including ethnic cleansing and firing at
civilians.

(Reporting by Humeyra Pamuk; Editing by Elaine Hardcastle and
Lisa Shumaker)