SANAA, Yemen -- Fighting between Saudi-led coalition forces and Yemen's Shiite rebels has flared up again around the Red Sea port city of Hodeida, despite U.N. calls for a cease-fire, Yemeni officials and witnesses said Tuesday.

The escalation, which followed a lull that had been in place since earlier this month, began late on Monday with coalition airstrikes hitting the rebels, known as Houthis, in and around Hodeida. Street fighting was also underway in the main Khamsin Str. in the city centre and in al-Saleh district. The officials spoke about the clashes on condition of anonymity because they were not authorized to talk to reporters; the witnesses did so for fear for their safety.

Information Minister Moammer al-Iryani, who is in Yemen's internationally recognized government, said the Houthis shelled the city centre and neighbourhoods held by government forces. Meanwhile, the rebel-run Al Masirah TV said the rebels attacked government forces on a main road linking the capital, Sanaa, and Hodeida. Government forces had captured the road in September.

Earlier, the rebels said they'd fired a ballistic missile the previous night into Saudi Arabia in response to an attempted border incursion and another airstrike, and that they reserved the right to respond to attacks. The missile came hours after the rebels said they would halt all rocket fire into Saudi Arabia for the sake of peace efforts.

The coalition has been attempting to retake Hodeida from the rebels since last summer, with its forces now 5 kilometres (3 miles) from the port, Yemen's traditional lifeline.

The renewed Hodeida fighting undermines the latest U.N. efforts to end the three-year war. Martin Griffiths, the U.N. envoy, announced on Friday that both sides had agreed to attend peace talks in Sweden "soon." Yemeni officials had said the next round of talks would take place on Nov. 29.

The Yemeni government said Monday it would attend the talks but also insisted the Houthis do so "unconditionally."

A U.N. draft resolution circulated by Britain on Monday urges the warring parties to relaunch peace talks and take urgent steps to address the humanitarian crisis. It also calls for an immediate cease-fire around Hodeida.

President and CEO of the International Rescue Committee, David Miliband, said Tuesday the draft resolution is "a vital diplomatic step and the best hope" toward a cease-fire and though only focused on Hodeida, "represents a critical development following the breakthrough call by the U.S. government for a ceasefire in Yemen."

The Trump administration late in October called for an urgent halt to the war and negotiations aimed at a political settlement.

The U.S.-backed, Saudi-led coalition has been battling the rebels on the side of Yemen's internationally recognized government since March 2015 in a war that has killed tens of thousands of people and pushed much of the country to the brink of starvation.