Fighting between Yemen's warring rivals escalated in the strategic port city of Hodeidah yesterday, one day before a U.N.-brokered cease-fire goes into force, according to a military source and local residents.

The sounds of powerful explosions were heard across the city's southern neighborhoods, the military source said on condition of anonymity, due to restrictions on speaking to the media. The source said Houthi rebels were shelling positions of government forces in the city. "The Houthis are adamant about undermining any ceasefire deal," the source said. The pro-Houthi Al-Masira television, for its part, said government forces had pounded the southern neighborhoods in Hodeidah. According to the broadcaster, four people, including a child, were injured in the attack.

Kamal Abdul Ghani, a local resident, said clashes were raging in the city since late Sunday. "Although the violence stopped this morning, it broke out again," he said, as reported by Anadolu Agency (AA).

Yemeni Foreign Minister Khalid al-Yamani earlier said the fragile cease-fire between government forces and rebels goes into force in Hodeidah today. The deal was reached during U.N.-sponsored peace talks held between the two warring rivals in Sweden last week. The agreement consists of a set of proposals, including one for a political framework for a post-war Yemen, the reopening of the airport in the capital, Sanaa, and a proposal for Hodeidah, a lifeline for millions of Yemenis dependent on international aid. The two sides also agreed to meet again in late January for more talks to define the framework of negotiations on a comprehensive peace settlement.

Yemen lies beside the southern mouth of the Red Sea, one of the most important trade routes in the world for oil tankers. It has been wracked by conflict since 2014 when Shiite Houthi rebels overran much of the country. Saudi Crown Prince Mohammed bin Salman, former Saudi defense minister, and Saudi Arabia's allies launched Operation Decisive Storm in March 2015. Civilians have borne the brunt of the conflict. The last available U.N. figure for the civilian death toll was published in 2016 and stood at more than 10,000. The Armed Conflict Location & Event Data Project, which tracks violence in Yemen, puts it at around 57,000 people.