(JNS) An attempt to seize an unmanned surface vessel operated by the U.S. 5th Fleet in the Persian Gulf was thwarted by the U.S. Navy, according to a statement.

Officials say that at 11 p.m. on Monday, Iran’s Islamic Revolutionary Guard Corps seized an American sea drone in Gulf waters and tried to tow it away, reported the AP. However, they only let go of the unstaffed vessel when a U.S. Navy warship and helicopter approached.

While the interception concluded without incident, tensions remain high between Washington and Tehran as negotiations over Iran’s fraying nuclear deal with Western powers linger.