A large fire broke out at a key oil facility in the United Arab Emirates on Monday after Iran fired 19 missiles and drones at the Gulf nation in a “dangerous escalation” of the Middle East conflict, local officials said.

The UAE said it had come under attack for the first time since the US-Israel cease-fire with Iran was secured last month, with Tehran accused of hitting the Fujairah Oil Industry Zone, the country’s largest port and oil storage area.

The blast left three Indian nationals injured, Abu Dhabi said, slamming the attack as a form of “dangerous escalation” as Iran and the US traded fire along the Strait of Hormuz on Monday.

Along with hitting the Fujairah plant, a UAE tanker was hit by projectiles just seven nautical miles north of the facility, according to the UK Maritime Trade Operations (UKMTO).

Another UAE vessel traveling north of Dubai and one traveling by Mina Saqr both suffered fires on board, UKMTO reported.

The cause of the fires on the two ships was not immediately verified but came just before Iran allegedly began its attack on the UAE.

The UAE, which has maintained a strong relationship with the US and Israel, blared its emergency sirens throughout the morning, calling on residents to take shelter repeatedly as projectiles came in.

In total, Iran fired 12 ballistic missiles, three cruise missiles, and four drones on Monday, the UAE defense ministry said.

Tehran has claimed that there had been no plans to target the UAE, Iran’s state-run broadcaster IRIB said.

Oman, a neighbor to the UAE, also reported an attack on the coastal town of Bukha located just past the Strait of Hormuz.

The blast hit a residential building, leaving two people injured and four cars damaged, Omani officials said, without identifying the cause of the explosion.

It remains unclear how the attacks around the Strait of Hormuz will affect the fragile cease-fire with Iran, with Adm. Brad Cooper, the head of US Central Command (CENTCOM), maintaining that the truce is still in place despite Tehran’s active fire on shipping vessels and US warships operating in the waterway.

The US has so far sunk at least six of Iran’s fast attack boats patrolling the strait, Cooper said, with at least two American ships crossing the chokepoint.

Iran, which reportedly hit a South Korean vessel also trying to cross after the US announced its escort services through the strait, has warned that it will maintain its control on the Strait of Hormuz, which saw the transport of 20% of the world’s oil supply before the war began.