NEW DELHI: A five day humanitarian ceasefire has come into effect in Yemen, although tensions remain high between the country’s Shiite rebels and the Saudi and US-backed government forces.

Just hours before the break in hostilities was due to take effect, the Saudi-led coalition targeted Yemen’s capital Sana’a with airstrikes. At the same time, US officials raised an alarm over an Iranian cargo ship that Tehran says is carrying humanitarian aid to Yemen. Iran, according to the pro-government forces in Yemen and the Saudi-led block, is aiding the Houthis -- a charge that Tehran vehemently denies.

The ceasefire, however, went into effect as scheduled. The plan for the ceasefire was put forth by the United States and Saudi Arabia, with US Secretary of State John Kerry and Saudi Foreign Minister Adel Al Jubeir announcing it at a conference on Friday. “Don’t shoot. Don’t move around and start to reposition and take advantage of this,” said Kerry. “This is a humanitarian pause and they should treat it accordingly.”

The timing of the ceasefire is crucial, as Yemen -- one of the poorest Arab states -- is struggling to cope with the devastation following over a month of violence and airstrikes. The United Nations says that 1000 Yemenis have died in the six weeks of fighting, since the Saudis launched airstrikes on March 26. Relief workers have warned of a dire situation as civilians in Yemen remain in need of urgent medical and food supplies.

However, the last attempt at a pause in fighting was short lived. Hours after Saudi Arabia announced that it was ending its air campaign in Yemen about two weeks ago, fresh airstrikes pounded the war-torn country. Air strikes were reported in the port city of Aden and the central city of Taiz, as fighting broke out between Houthi rebels and pro-government forces in Aden and the city of Lahj, the capital of Huta, and the southern town of Daleh.

The Saudi government had announced that that it was ending its air campaign dubbed operation "Decisive Storm" and replacing it with a new campaign aimed at protecting civilians and preventing Houthi fighters from operating.

Brigadier-General Ahmed al-Asiri, the coalition's spokesperson made the announcement, saying that the coalition had achieved its targets in Yemen, the General said that a new operation called "Renewal of Hope" was being initiated and came into effect at midnight local time. "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,” Asiri said.

Yemen's Saudi and US-backed President Abd-Rabbu Mansour Hadi made a televised speech before that from Riyadh. "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.

Houthi leaders seem to have welcomed the move, telling Reuters news agency that a political deal to end the conflict had almost been reached.

The peace, however, was short-lived. Houthi rebels meanwhile called for peace talks, with Houthi spokesperson Mohammed Abdulsalam posting on Facebook that UN sponsored talks should resume "but only after a complete halt of attacks.”

Since then, the attacks have continued. At the time of writing, whilst the Saudi and Houthis reiterated their support for the ceasefire, fresh airstrikes pounded Yemen. On Saturday alone, the Saudi-led coalition hit Yemen with 130 air strikes over the previous 24 hours, with a senior US official saying that some of the strikes violated international law.

"The indiscriminate bombing of populated areas, with or without prior warning, is in contravention of international humanitarian law," the U.N. Humanitarian Coordinator for Yemen Johannes van der Klaauw said in a statement later in the day.

"Many civilians are effectively trapped in Saada as they are unable to access transport because of the fuel shortage. The targeting of an entire governorate will put countless civilians at risk."