Saudi Arabia issued an air raid alert in Riyadh early Saturday after explosions were heard in the capital amid continued Houthi attacks.

Residents received a warning shortly before 3am local time saying the area was under a “hostile aerial threat” and urging them to stay indoors. Foreign journalists later heard two explosions in Riyadh.

Saudi Civil Defence lifted the alert around half an hour later and issued an all-clear. Authorities also urged residents to avoid gathering in crowds.

The alert marked the first time Riyadh had faced such a warning since the Houthis stepped up attacks and declared a “maritime embargo” against Saudi Arabia in July.

The Saudi Civil Defence had issued alerts for Riyadh and several other regions late Friday and early Saturday as tensions between the Kingdom and the Houthis continued.

The developments come as Houthi attacks have also disrupted shipping through the Bab al-Mandab Strait, a key route for Saudi exports. Data from maritime tracking firm Kpler showed that only five vessels carrying Saudi products left the Red Sea through the strait in the previous seven days.

The figure was the highest weekly total since July 24, when 11 vessels carrying Saudi products passed through the route. Crude shipments through the strait have also remained below usual levels.

Pakistan has condemned Houthi attacks on merchant ships in the Bab al-Mandab Strait and called for an immediate end to the attacks.

“We call upon [the] Houthi militia for immediate cessation of these provocative acts which could have dire consequences for maritime security, and regional peace and stability,” Pakistan’s Permanent Representative to the United Nations (UN), Ambassador Asim Iftikhar Ahmad, told a UN Security Council Arria Formula meeting convened by Bahrain.

Ahmad said that the attacks seriously undermine maritime security and threaten peace and development in regional countries, “especially the Kingdom of Saudi Arabia”, which he added was facing “blatant and unprovoked aggression” by the Houthis.

The Houthis have also claimed that Saudi Arabia carried out 26 strikes on areas under their control in Yemen over the past 24 hours. The group further claimed that Saudi strikes on its positions reached 300 over the past wee

The Houthis said that their maritime blockade against Saudi-linked shipping came in response to what they described as a Saudi blockade of ports and airports in areas under Houthi control.

The group has also attacked Saudi oil facilities with drones and missiles, with the attacks causing fires and temporarily disrupting operations.

Saudi Crown Prince Mohammed bin Salman (MBS) has also asked the United States (US) President Donald Trump to take military action against the Houthis, according to two sources familiar with the matter who spoke to an international media outlet. Trump has declined to directly involve US forces, the sources said, while offering intelligence and targeting support.