BAMAKO, Mali — Officials in Mali condemned Islamist militants on Friday for chopping off a man’s hand for allegedly stealing sheep, a punishment underscoring hardliners’ tightening control over northern Mali.

The amputation of the 35-year-old man’s hand was carried out Wednesday in the northern village of Ansongo. His codefendant’s punishment was postponed because he was found to be ill.

“After the Islamists cut off the young man’s hand, they put his arm in boiling oil,” said a witness at the scene who spoke on condition of anonymity for fear of reprisals.

Authorities expressed outrage over the latest punishments the Islamists have said are in accordance with strict Sharia law.

Late last month, they stoned an adulterous couple to death.

“It’s a horror what is happening in our cities,” said El Hadj Baba Haidara, a member of the Malian Parliament.

The Malian government issued a statement condemning the amputation, calling it “a new horrible act to add [to] their long list.”

The statement said the government is open to accelerating plans with neighboring nations to recapture the north from rebel hands.

Mali’s north was overrun by a mix of armed groups — including several allied with Al Qaeda — following a coup in Mali’s capital, Bamako, in March.

Since June, Islamists have exerted full control of the northern half of the country and have imposed Sharia law.

UN Secretary General Ban Ki-moon this week warned of worsening security and humanitarian crises in Mali and asked the Security Council to consider financial and travel sanctions on rebels and Islamist fighters, including several allied with Al Qaeda.