According to Yemeni security officials, the coalition airstrikes hit rebel positions and tanks in several of Aden's neighborhoods.

The truce which expired at 11 p.m. local time (2000 UTC) on Sunday was intended to facilitate desperately needed humanitarian aid to the southern port city.

The renewed attacks followed talks earlier on Sunday between 400 Yemeni politicians and tribal leaders in Saudi Arabia. The talks which are set to last until Tuesday have been boycotted by Houthi rebels, meaning that the national dialogue is unlikely to end the ongoing violence in Yemen.

Opening talks on Sunday was UN envoy to Yemen Ismail Ould Cheikh Ahmed who called on all parties to ensure a lasting truce.

"I call on all parties to refrain from any action that disturbs the peace of airports, main areas and the infrastructure of transport," said Ahmed, speaking on behalf of UN Secretary-General Ban Ki-moon.

Push for an extenstion

Khaled Bahah, the vice president of Yemen's internationally-recognized government, said his administration was also in favor of extending the ceasefire.

"There is an effort for an extension, but it depends on how it is on the ground," Bahah said.

"But it's our wish from the government side that we need to extend it," he added.

Rising civilian deaths

According to UN figures, more than 1,400 people, many of whom were civilians, have been killed in Yemen's conflict since March 19.

As the result of a Saudi-led blockade, Yemen's population of 25 million has also endured shortages of food, water, medicine and electricity, prompting the much-needed ceasefire over the past five days.

ksb/rc (AFP, AP, Reuters)