Saudi Arabia says its East-West oil pipeline was struck in the Medina region on Monday, starting a limited fire that was quickly extinguished, in the latest attack on the kingdom's energy infrastructure.

An official at the Saudi Energy Ministry told the state-run Saudi Press Agency that no injuries or fatalities were reported and that pipeline operations were unaffected.

Saudi officials did not name those responsible for the strike. Yemen's Iran-backed Houthis have repeatedly targeted Saudi oil infrastructure with drones and missiles, and analysts at the Institute for the Study of War assessed that the Houthis likely carried out Monday's strike.

A vital Hormuz bypass

The East-West pipeline, also known as Petroline, runs about 1,200 kilometres from the Abqaiq oil fields in Saudi Arabia's Eastern Province to the Red Sea port of Yanbu.

It is the kingdom's main route for getting crude to market without passing through the Strait of Hormuz, which Iran has kept effectively closed to commercial traffic during the war that began in February.

Saudi Aramco converted the pipeline's second line to carry crude in March, raising its capacity to about seven million barrels a day. The line has become central to Saudi exports while Gulf shipping remains disrupted.

The pipeline has been hit before. A Houthi attack on a pumping station in September forced Saudi Arabia to shut the line for about 11 days for emergency repairs, according to the Institute for the Study of War.

Missiles intercepted over Riyadh

Hours after the pipeline strike was reported, the Saudi-led coalition fighting the Houthis said its forces had intercepted missiles aimed at Riyadh and the south of the kingdom, as well as a drone over the Eastern Province.

Coalition spokesperson Major-General Turki al-Maliki blamed the Houthis for the launches. The group did not immediately claim responsibility.

The Houthis said on Sunday that they had attacked the Aramco Tower in Riyadh's financial district. Saudi Arabia's Energy Ministry said the tower suffered limited damage, with no injuries, and did not identify those responsible.

On Tuesday, Riyadh's deputy governor, Prince Mohammed bin Abdulrahman bin Abdulaziz, inspected an Aramco administrative building in the capital that was damaged in the attack. He said the incident showed the Houthis were targeting civilian facilities, according to the Saudi Press Agency.

Escalating campaign

The Houthis have stepped up strikes on Saudi infrastructure in recent weeks, including Aramco's headquarters in Dhahran in the Eastern Province.

Fighting between the Houthis and the coalition backing Yemen's internationally recognised government intensified after the Houthis advanced in September towards the Bab el-Mandeb Strait, a strategic chokepoint at the southern end of the Red Sea.

The Houthis say their campaign aims to press Saudi Arabia to end its military operations in Yemen and accept their demands, which include lifting Saudi controls on ports and airports in Houthi-held areas and handing the group control of Yemen's oil and gas resources.

The latest strikes underline how the war in Yemen and the wider confrontation with Iran are now hitting Saudi Arabia's energy lifeline.