An unknown number of aid workers are missing after air strikes hit a hospital in South Sudan, near the Ethiopian border, a charity group says. The hospital, run by medical charity Doctors Without Borders (MSF), was reportedly hit during the night on Tuesday by South Sudan government forces. The government has yet to respond. In a separate incident on the same day, MSF's health facility in Pieri, also in Jonglei state, was looted by unidentified assailants, rendering it unusable for the community.

'Our colleagues had to flee with the community and their fate and whereabouts are still unknown,' MSF stated. There has been a resurgence in fighting in Jonglei state between government forces and those loyal to First Vice-President Riek Machar, heightening concerns of a return to full-blown civil war in the young nation.

The United Nations reported that around 280,000 people have been displaced in Jonglei since December, largely due to fighting and aerial strikes. MSF has been facing targeted violence, marking eight assaults against its facilities last year alone.

In advance of Tuesday’s airstrike, MSF had received warnings about a possible attack, allowing for the evacuation of patients hours before. Still, the hospital's main warehouse and essential medical supplies were destroyed. MSF warned that ongoing attacks on its facilities threaten healthcare access for around 250,000 people in the area, underlining the dire humanitarian situation. 'While we are aware of the immense needs in the country, we find it unacceptable to be a target for attacks,' said Gul Badshah, MSF's operations manager.