As of May 15, 1,849 people had been killed and 7,394 had been injured, the UN humanitarian agency said citing numbers from Yemen health facilities.The UN has repeatedly stressed that actual toll could be higher.

The announcement came as Saudi-led warplanes hit Sanaa, in the first strikes on the capital since the end of a five-day humanitarian truce on Sunday.

The Saudi-led coalition has waged an air war on the Yemen since late March in an effort to restore the authority of exiled President Abedrabbo Mansour Hadi, who is now based in Riyadh.

"The humanitarian pause in Yemen was not long enough to reach all those in need of food," Elisabeth Byrs, spokeswoman for the UN World Food Programme, told reporters.

She said WFP had managed to deliver food to only 400,000 people during the pause, just over half of the 738,000 it had aimed to help.

WFP is appealing for a series of predictable breaks in the conflict to deliver desperately needed aid," she said.

The assessments revealed that the violence had forced far more people to flee their homes since previously thought, according to UN refugee agency spokesman Adrian Edwards.

The number of people displaced since late March within the conflict-ravaged country is now estimated to be more than 545,000, he said, compared to the 450,000 announced last Friday.

They join some 330,000 people already internally displaced before the latest conflict, and some 250,000 Somali refugees inside Yemen believed to be impacted by the fighting, Edwards said.Around 29,000 other Yemenis have fled to neighboring countries.

Today Saudi fighter jets targeted residential areas in the Northwestern Yemeni province of Saada, leaving dozens of people dead and injured.

The Saudi warplanes pounded civilian areas in Southern Saada and claimed the lives of large groups of people in their 55th day of aggression against the impoverished country.

Earlier today, one woman and a child were also martyred in Saada after the kingdom's bombers targeted the province.

On Monday, the capital city of Sanaa was repeatedly pummeled by Riyadh's jets two days after a truce expired.

Saudi Arabia launched its bombing campaign against Yemen on March 26 in an attempt to restore power to fugitive President Mansour Hadi, a staunch ally of Riyadh.

Hadi stepped down in January and refused to reconsider the decision despite calls by Ansarullah revolutionaries of the Houthi movement.

Despite Riyadh's claims that it is bombing the positions of the Ansarullah fighters, Saudi warplanes are flattening residential areas and civilian infrastructures.

According to FNA tallies, the Monarchy's attacks have so far claimed the lives of at least 3,815 civilians, mostly women and children.

On April 21 and May 12, Saudi Arabia declared end to Yemen airstrikes after weeks of bombings, but airstrikes are still underway.

In a bid to facilitate aid deliveries to the improvised country, Yemen's Ansarullah and army accepted a five-day humanitarian ceasefire proposed by Saudi Arabia. However, Riyadh violated the ceasefire for several times.