The Saudi-led coalition that has been bombing Yemen for almost a month says its military operation "Decisive Storm" has ended and a new campaign aimed at protecting civilians and preventing Houthi fighters from operating has begun.

Brigadier-General Ahmed al-Asiri, the coalition's spokesperson, said on Tuesday that the coalition had achieved its military goals in Yemen and a new operation, called "Renewal of Hope", would aim to protect civilians and combat "terrorism".

The new operation started at midnight on Tuesday local time (22:00 GMT).

Fresh strike reported

However, the deputy governor of Aden Nayef Al Bakri told Al Jazeera that the Saudi-led coalition conducted an air strike against Houthis in Aden early on Wednesday. The raid targeted tanks which were being moved into areas in the city that were captured earlier, Al Bakri said.

Yemen's President Abd-Rabbu Mansour Hadi gave a televised address from Riyadh, where he thanked the coalition partners for their support.

"I extend on my behalf and on behalf of the Yemeni people sincere thanks and appreciation for the Arab and Muslim brothers and our partners in the coalition for supporting legitimacy," he said.

A few hours after the coalition announcement, senior Houthi leaders said a political deal to end the conflict had almost been reached, the Reuters news agency reported.

Asiri hailed "Decisive Storm", a military campaign launched by Saudi Arabia and Arab allies on March 26, a "success". He called the new operation a "combination of political, diplomatic and military action".

"The coalition has completed the 'Decisive Storm' campaign at the request of the Yemeni government and the president of Yemen," Asiri said.

"The primary goals of the campaign have been achieved and sovereignty has been protected.

"We are able to confirm that the Houthis are no longer a threat to Yemenis or neighbouring countries.

"The Yemeni government will now undertake all necessary actions to start rebuilding the country."

However, Asiri did not rule out future air strikes against the Houthis and said the coalition would continue to impose a naval blockade on Yemen.

The United States welcomed the coalition's announcement in a statement issued by National Security Council spokesman Alistair Baskey.

"We continue to support the resumption of a UN-facilitated political process and the facilitation of humanitarian assistance,” the statement said.

Saudi Arabia's Ministry of Defence had earlier said that all heavy weapons and ballistic missiles belonging to the Houthis had been destroyed, that they had imposed restrictions over Yemen's airspace, and that any possible threats on the kingdom and neighbouring countries had been removed.

Al Jazeera's Mohamed Vall, reporting from Jizan on the Saudi-Yemen border, said there had been signs that a change in policy was on the horizon.

"Iranian officials were optimistic of a ceasefire earlier in the day with US naval ships arriving in the region and greater levels of contact between the US and the Saudi monarchy," Vall said.

"Most likely Iran, Saudi Arabia and others have come to some kind of agreement on the conflict."

Timeline: The rise of Yemen's Houthi rebels

The coalition announcement came hours after Riyadh said it was preparing to send its elite National Guard to reinforce its border with Yemen.

The National Guard is regarded as the country's best equipped military force, and until now has not been involved in the campaign.

Led by Miteb, the son of the late King Abdullah, the unit is recruited from tribes that have traditionally backed the Saudi royal family.

Earlier on Tuesday, the US defence department confirmed to Al Jazeera that it was sending the USS Theodore Roosevelt and Normandy to ensure vital shipping lanes in the region remain open and safe.

The narrow Bab el-Mandeb strait is a strategic passage separating Yemen from East Africa and serves as a key trade and oil route linking Europe to the east.

Civilians struggle to cope as Yemen conflict escalates

The World Health Organisation (WHO) had earlier reported on Tuesday that violence between March 19 and April 17 had killed 944 people and wounded 3,487, and warned that the impoverished nation's health services were on the brink of collapse.

The WHO said the number of patients able to access health facilities had plummeted since the escalation of hostilities, with a 40 percent drop in the number of daily consultations.

Prices of essential medicines have increased by more than 300 percent, and the shortage of water has increased the risk of diarrhoea and other diseases and is affecting basic hygiene in hospitals and clinics.