Japanese police arrested a U.S. Air Force captain Saturday on suspicion of drunk driving in Okinawa, a police spokesman said, in the latest twist to strains between the Pacific allies.

The arrest comes just a week after Tokyo and Washington agreed to measures aimed at preventing crimes by U.S. service members on the island of Okinawa after a murder allegedly involving an American Marine triggered outrage.

The U.S. military has around 54,000 personnel stationed in Japan, mostly on Okinawa. Crimes committed by its members have been a thorn in relations between the close security allies.

U.S. officials also said last week they would extend a curfew to lower-ranking service members through Dec. 7, while banning all service members from drinking alcohol outside their homes between midnight and 5 am.

Police arrested the 27-year-old as he ¡°was driving on a road in Okinawa City at around 3:09 am Saturday,¡± a spokesman for Okinawa prefectural police said.

¡°It is not clear if he violated the curfew¡± imposed by U.S. officials, he said.

The arrested captain was assigned to Kadena Air Base on Okinawa, Kyodo News reported.

Officials at the base were not immediately available for comment.