Bahrain issued two alerts of potential threats on Sunday, its first such warnings since September, as Iran said it had attacked a U.S. base in the Gulf country amid uncertainty over a U.S.-Iran deal aimed at ending the nearly 9-month-old war. Iran's Islamic Revolutionary Guard Corps said it had attacked a U.S. military base in Bahrain in retaliation for "hostile U.S. actions," Iran's Fars news agency reported.

The Revolutionary Guard said it had launched six drones targeting a U.S. air-defense radar at the Al-Rifaa helicopter base in Bahrain, according to Iranian state-run Press TV. Explosions could be heard around 4 a.m. local time, with residents reporting a second series of blasts around 6:30 a.m. There was no immediate confirmation from U.S. or Bahraini authorities. Two days earlier the Revolutionary Guard had said it attacked a U.S. early-warning radar in Bahrain, a claim the U.S. military denied, saying it had intercepted two Iranian drones without any damage.S1S2

Bahrain, home to the U.S. Navy's 5th Fleet, urged citizens and residents to remain calm and proceed to the nearest safe location, the interior ministry said, though it gave no further details on the threats. The alerts come as diplomatic efforts to end the conflict have yet to produce a breakthrough. The war began with U.S. and Israeli strikes on Iran on Feb. 28 and then spread across the region, with Tehran launching missile and drone attacks on U.S. bases in Gulf countries.S1S2

President Donald Trump has said in recent days that he might hold off on attacking Iran if the U.S. faces no new provocations from Tehran or the Iran-backed Houthis in Yemen, but that he would maintain a U.S. naval blockade. On another front, the Houthis and the Saudi-led coalition fighting them have continued to exchange attacks. On Sunday the coalition said it had intercepted two Houthi ballistic missiles launched toward the Saudi capital Riyadh and three drones in the kingdom's oil-rich Eastern Province.S1S2