Riyadh (AFP) April 21, 2015 –  Saudi-led coalition declared an end Tuesday to four weeks of air strikes in Yemen, saying the threat of Iran-backed rebels there had been removed and that operations are entering a political phase.

However, it left open the option of resuming strikes if the movements of the Houthi rebels warrant it, while adding that a naval blockade on the strategic country at the tip of the Arabian Peninsula will continue.

The announcement came as a US aircraft carrier was headed to the Arabian Sea, with Washington saying it was monitoring Iranian vessels suspected of carrying weapons to the rebels in violation of a UN embargo.

The coalition has “ended Operation Decisive Storm based on a request by the Yemeni government and President Abedrabbo Mansour Hadi,” its spokesman, Brigadier General Ahmed al-Assiri, said in Riyadh.

The operation, which began March 26, will continue until midnight.

A coalition statement said the next step would aim to resume the political process in Yemen, delivering aid and “fighting terrorism” in the country, home to a deadly Al-Qaeda franchise.

The Saudi defense ministry said the air strikes had managed “to successfully remove threats to Saudi Arabia’s security and that of neighboring countries”.

 A man walks past a vehicle that was damaged the day before during an air strike by Saudi-led coalition

The UN health agency said more than 900 people have been killed since the strikes were launched against rebels clashing with pro-government forces.

And the International Organization for Migration announced a suspension of its evacuation efforts due to insecurity.

Amid reports of a nine-ship Iranian convoy in the area, the US Navy said it was sending in the USS Theodore Roosevelt and guided-missile cruiser USS Normandy.

Located on key shipping routes and bordering oil-rich Saudi Arabia, Yemen was plunged into chaos last year when the Huthis seized Sanaa.

The coalition of Sunni Arab nations launched the strikes in a bid to restore the authority of Hadi, who fled to Riyadh as the Shiite rebels advanced on his southern refuge Aden.

Overnight, they pressed the strikes against the rebels and their allies in the security forces, as the civilian death toll from a Monday raid on a missile depot in the capital rose to 38.

The coalition says it has carried out more than 2,000 strikes, gained complete control of Yemeni airspace and knocked out rebel infrastructure.

The World Health Organization said the violence had killed 944 people and wounded 3,487 as of April 17.