Bahrain said Iranian drones targeted its air navigation systems on Monday, though traffic remained unaffected, while Kuwait also reported attacks as the United States and Iran traded strikes.
A shaky US-Iran ceasefire has all but collapsed as Iran began attacking vessels using an Omani route in the Strait of Hormuz.
In response, the US has attacked Iran, which has responded with strikes on the Gulf and other Arab countries.
"As a result of a hostile Iranian act of aggression against the Kingdom of Bahrain, civil air navigation systems... were targeted by hostile drones," Bahrain's aviation authority said.
"However, air navigation operations remained unaffected," it added.
Bahrain's military had said in the morning that it "intercepted and destroyed a number of Iranian aerial attacks".
Bahrain’s Foreign Ministry strongly condemned the repeated Iranian attacks targeting the kingdom's civilian and vital facilities with missiles and drones.
It slammed them as a "blatant violation of Bahrain’s sovereignty, security, and stability, a direct threat to civilians, and a breach of international law, international humanitarian law, the UN Charter, principles of good neighborliness, and international legitimacy resolutions."
The ministry also condemned the targeting of civilian air navigation systems, saying that it poses a "serious threat to the safety of international civil aviation, as well as the lives of passengers and flight crews."
The attack violates the Chicago Convention on International Civil Aviation and resolutions of the International Civil Aviation Organization (ICAO), it added, calling it a "grave breach of international customs and pacts that prohibit targeting civilian facilities."
The ministry underscored the kingdom’s right to take all legitimate measures to protect its sovereignty, security and stability and defend its territories and vital facilities in line with the UN Charter and international laws.
The General Command of the Bahrain Defense Force said all military branches and units are at the highest state of readiness and fully prepared to defend the kingdom.
It urged citizens and residents to avoid approaching any foreign or suspicious objects that could be remnants of the attacks, and to report them immediately.
Kuwait's military also said on Monday it was responding to renewed missile and drone salvos.
"Kuwaiti air defenses are currently confronting hostile missile and drone attacks," the army said in a statement blaming Iran.
Both Kuwait and Bahrain have borne the brunt of attacks by Iran on its Gulf neighbors since hostilities resumed this month.
Bahrain has accused Iran of targeting civilians, while Kuwait has reported Iranian attacks on water and electricity plants as well as oil facilities.
