(Bloomberg) -- Fighting between Ethiopian government troops and forces loyal to the rebel northern state of Tigray is continuing despite the fall of the regional capital, Mekelle, the dissidents’ top leader said.

Clashes are ongoing in two locations near Mekelle and two others 60 kilometers (38 miles) north of the city, Debretsion Gebremichael, the leader of the Tigray People’s Liberation Front, which previously controlled the state, said in a text message on Friday. Most of the fighting has involved forces from neighboring Eritrea, which has been backing the federal government, he said.

The TPLF’s strategy is “to inflict heavy casualties in terms of human, material and moral” damage on the federal and Eritrean forces, he said. “We are achieving our objective.”

Prime Minister Abiy Ahmed ordered an incursion into Tigray a month ago, the culmination of months of tension between his administration and the TPLF -- the erstwhile power broker in the country’s ruling coalition. There have been heavy casualties during the fighting, although no accurate numbers are available, and tens of thousands of people have been displaced.

With telecommunications to most of Tigray cut off, it has been difficult to independently monitor the progression of the fighting or verify the opposing sides’ versions of what transpired.

Abiy has previously said federal forces had taken control of most of Tigray. His spokeswoman Billene Seyoum and Redwan Hussein, the state foreign minister and spokesperson for the government’s Emergency Task Force, didn’t immediately respond to requests for comment on the TPLF leader’s claims. Eritrea’s government hasn’t commented on whether its forces are involved in the conflict.

The government seized control of Mekelle from the TPLF last weekend.

At least 27 civilians were killed and more than 100 seriously injured during heavy shelling of the city, according to two doctors who work at its Ayder Referral Hospital and did not want to be identified because they feared government reprisals. One of them supplied photos of people admitted to the facility with shrapnel wounds and trauma injuries.

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On Thursday, one person was killed and four were injured during clashes that ensued after youths demonstrated in Mekelle, the doctors said. The Ayder hospital ceased operating on Friday because its electricity supply was cut off and it ran out of key supplies, they added.

Debretsion also said Tigray civilians has staged protests in Mekelle as well as in the nearby town of Axum, and that several people died after federal forces opened fire on them.

Many of Mekelle’s roads have been blocked with large stones and federal military officers are maintaining a heavy presence, according to the doctors. The situation in the city remains extremely tense, with bands of young men in civilian clothes roaming the streets and looting properties, one of them said.

On Dec. 2, the United Nations said it had secured an agreement with the Ethiopian authorities to provide “unimpeded, sustained and secure access” for the delivery of emergency relief to government-controlled parts of Tigray. UN and European Union officials said they are conducting security and road assessments this week with a view to begin delivering aid next week.

Read more: EU May Suspend Budget Funding to Ethiopia Over Tigray Conflict

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