A senior Ethiopian official accused militiamen in the Amhara region of seeking to overthrow the regional and federal governments following days of fighting that led the authorities to declare a state of emergency.

Clashes between Fano militiamen and the Ethiopian National Defence Force (ENDF) continued over the weekend. Residents of Gondar, Amhara’s second-biggest city, said that heavy weapons fire that began on Sunday could be heard into Monday morning.

The conflict has quickly become Ethiopia’s most serious security crisis since a two-year civil war in Tigray region, which neighbours Amhara, ended in November.

Temesgen Tiruneh, director-general of Ethiopia’s national intelligence service who was appointed to oversee enforcement of the state of emergency, acknowledged that militia fighters had taken some towns and districts.

“This robbery force is operating with the goal and intention of overthrowing the regional government by force and then advancing to the federal system,” Temesgen said in comments broadcast late on Sunday by state-affiliated Fana Broadcasting.

The state of emergency declaration gives the security services the power to impose curfews, restrict movement, ban the carrying of guns and sharp objects, ban public gatherings and make arrests and conduct searches without warrants.

Government spokesperson Legesse Tulu said on Saturday that the authorities had already started to arrest those behind the unrest.

Fano is a part-time militia that draws volunteers from the local population and was an ally of the ENDF during the Tigray War.

Their relationship later deteriorated, in part over recent efforts by federal authorities to weaken regional paramilitary groups. Some activists say this has left Amhara vulnerable to attack by neighbouring regions.

Violent protests erupted across Amhara in April after Prime Minister Abiy Ahmed ordered that security forces from Ethiopia’s 11 regions be disbanded and integrated into the police or national army.

Protesters accused the government of trying to undermine Amhara’s security. The government denied this and said the move was needed to ensure national unity.