Tigrayan rebels were urged by Ethiopia’s government to join a unilateral ceasefire in their conflict on Thursday as aid agencies struggled to reach hundreds of thousands of people facing famine.

The Tigray People’s Liberation Front (TPLF), the former rulers of Ethiopia’s Tigray region, said on Monday it was back in control of the regional capital Mekelle after nearly eight months of fighting.

The government declared a unilateral ceasefire but the TPLF dismissed it as a joke. Hostilities persisted on Thursday and pressure built internationally for all sides to pull back.

“Operations are under way … and the number of prisoners of war is increasing by the minute,” TPLF spokesman Getachew Reda told Reuters by satellite phone, with light artillery fire crackling in the background.

A bridge over the Tekeze River near the northern town of Shire has been destroyed, so getting aid to the region will be “even more severely hampered” than before, the International Rescue Committee said.