Witnesses in Sudan’s capital Khartoum reported artillery fire, fighter-jet flights over the city, and continued street battles in some areas as a weeklong ceasefire got off to a shaky start.

Heavy bombardment could be heard in east Khartoum and one resident shared a photo of thick black smoke rising into the sky. In Omdurman and Khartoum North, Khartoum’s twin cities, people said they heard sounds of small arms firing.

After five weeks of fierce battles between the army and the paramilitary Rapid Support Forces (RSF), the warring factions agreed to a seven-day truce starting at 9:45pm (19:45 GMT) on Monday to allow the delivery of aid and let people escape.

In the hours before the ceasefire went into effect, Sudan’s army conducted heavy air strikes across Khartoum against its paramilitary rivals.

The ceasefire includes for the first time a monitoring mechanism involving the army and the RSF, as well as representatives from Saudi Arabia and the United States, which brokered the agreement after talks in Jeddah.

Shortly before the truce took effect, RSF released an audio message from its commander – Mohamed Hamdan Dagalo, known as “Hemedti” – in which he thanked Saudi Arabia and the US but urged his men on to victory. “We will not retreat until we end this coup,” he said.

Both sides accused each other of an attempted power grab at the start of the conflict on April 15.

The ceasefire has raised hopes of a pause in a war that has driven nearly 1.1 million people from their homes, including more than 250,000 who fled into neighbouring countries, threatening to destabilise a volatile region.