Dissident leaders of Ethiopia’s war-hit Tigray region have dismissed a government ceasefire declaration and vowed to drive out “enemies” from the region, after rebel fighters advanced on the Tigrayan capital. Federal security forces and officials from the central government appointed interim administration fled Mekelle on Monday night. Residents took to the streets in jubilation, firing celebratory gunfire and fireworks into the sky. An overnight statement from the Tigray People’s Liberation Front (TPLF) hailed the advances of the Tigrayan fighters, and declared Mekelle was fully under its control, vowing to drive out “enemies” from the federal government. “The government of Tigray calls upon our people and army of Tigray to intensify their struggle until our enemies completely leave Tigray,” the statement said. “The government and army of Tigray will carry out all the tasks necessary to ensure the survival and security of our people.” TPLF spokesman Getachew Reda told AP “we’ll stop at nothing to liberate every square inch” of Tigray and rejected the unilateral ceasefire Ethiopia’s government declared on Monday as a “sick joke”. Tigrayan forces also entered the key town of Shire on Tuesday, according to eyewitnesses, cementing a swift series of territorial gains in the northern region, forcing the Ethiopian military and its allies into retreat. “Everybody is welcoming them and celebrating. Now there are a lot (of Tigrayan forces) and most of them are in uniform,” one resident told Reuters. Shortly after TDF forces advanced on Mekelle, the Ethiopian government declared a “unilateral ceasefire”, in a rare attempt at de-escalating the war. The ceasefire “will enable farmers to till their land, aid groups to operate without any military movement around and engage with remnants (of the TPLF) who seek peace”, the statement said, adding that efforts continued to bring Tigray’s former leaders to justice. Ethiopia said the ceasefire would last until September, the end of the crucial planting season in the region. The government’s forces invaded Tigray in November, sparking global outrage and condemnation of the prime minister, and Nobel peace prize winner, Abiy Ahmed. The government said it had acted after rebel attacks on military bases, and the TPLF, which formerly ruled Ethiopia for nearly three decades, was ousted within six weeks. Close to a million civilians have been internally displaced and many have fled to neighbouring Sudan, sparking a humanitarian crisis. The presence of Eritrean forces and local ethnic militia groups in the fighting have deepened fears that worsening ethnic and historic divisions will have a lasting impact on the region. For months, the TDF appeared to have been subdued as the guerilla-style conflict wore on, but in recent weeks it launched a series of counter offensives. A surge in fighting coincided with Ethiopia’s national elections earlier this month, which were not held in Tigray. Though the TDF did not hold any major cities and towns for months, its leaders repeatedly boasted they were in the ascendancy and regrouping in remote rural areas. Residents had recently reported fighters advancing near the city, with the rebels boasting of inflicting major losses on federal forces. Last week, residents reported that flights to Mekelle were restricted, and as fighting intensified, officials were said to be denying permits for aid operations in towns outside of the city. The US welcomed the ceasefire announcement but hinted that Ethiopia and Eritrea could face further sanctions if hostilities did not reduce. “We will not stand by in the face of horrors in Tigray,” said Robert Godec, acting assistant secretary of state for the US state department’s Bureau of African Affairs. Godec urged Eritrea to formally agree to the ceasefire. The chair of the House of Representative Africa subcommittee, Karen Bass, also said, “Every effort must be made to make this ceasefire meaningful, including discussions with all parties to the conflict.” Britain, the US and Ireland have called for an emergency UN security council public meeting, which could happen on Friday, diplomatic sources told AFP. The security council has failed to hold a public session on Tigray since the war broke out, with many African countries, China, Russia and other nations deeming the crisis an internal Ethiopian affair. The eight-month conflict has been marked by large-scale atrocities. Earlier this month, 64 people were killed and 180 injured in a government airstrike on a market in the town of Togoga, according to local health workers and residents. Ethiopia said the airstrike targeted rebel fighters, but survivors and health workers said the attack was on a busy market and killed and injured dozens of people, including children. Aid agencies have been heavily restricted by Ethiopia’s government from providing desperately needed aid. About 350,000 people are on the brink of famine according to the UN. Abiy has denied that hunger exists in Tigray. Peter Smerdon, a spokesperson for the World Food Programme in Nairobi, said it had been forced to suspend operations in Tigray in the turbulence of recent days, but was now pressing for “full and immediate access” so that aid supplies could resume quickly. “Before this surge in fighting we already knew that people were undoubtedly starving to death – we don’t know in what kind of numbers – in areas that we could not reach; mainly rural areas cut off from the main roads, where we couldn’t reach either because of fighting or because we were turned around at checkpoints by parties to the conflict. So it’s a matter of life and death for people, for us, to resume our operations as soon as possible,” he said. But humanitarian organisations needed a guarantee that their workers would be safe in the field, he added. At least 11 aid workers – most recently three employees of Médecins Sans Frontières – have been killed in Tigray since November. The conflict in Tigray has been marked by several atrocities, including multiple massacres and sexual violence. Many have been linked to Ethiopian federal soldiers and their Eritrean allies.