Washington  — A Pentagon spokesman said the refueling and troop transport operations at the U.S. transit base in Manas, Kyrgyzstan, continue “unabated” by ethnic riots in the southern part of the country.

Pentagon spokesman Col. David Lapan told CNN that the violence in the south of Kyrgyzstan is about 200 miles from the transit base and operations there have not been affected.

The base, which is near the Kyrgyz capital, Bishkek, has not added any additional security measures, he said.

Refueling operations had been halted while the United States negotiated new fuel contracts with the interim government, he said, but late last week refueling started again.

Lapan said the U.S. military is examining what options it can provide for humanitarian assistance in connection with the violence in the south.

The transit center in Manas was opened in 2001, when U.S. military operations in Afghanistan began.