(CNN) -- Fighting erupted Tuesday in an autonomous region of Tajikistan after central government forces moved in on a former opposition warlord believed to be behind the killing of a top security general.
At least 12 soldiers and 30 opposition fighters were killed, said a statement from Tajikistan's security service. It said the military operation was continuing.
Residents described continuous gunfire in Khorog, the capital of the Gorno-Badakshan region, which borders Afghanistan. They said they believed the number of casualties was higher than the official toll.
Gorno-Badakshan was cut off Tuesday after communication lines, including cell phones and internet service, was severed.
The violence stemmed from the death of Maj. Gen. Abdullo Nazarov, head of the regional branch of the State Committee on National Security, a successor to the Soviet KGB.
Nazarov's car was stopped by a group of unidentified people, according to Ria-Novosti, a Russian state-run news service. Nazarov was pulled out of the car and stabbed several times. He died on the way to hospital, Ria-Novosti said.
Police arrested two suspects but were still seeking Tolib Ayombekov, the suspected leader of a smuggling ring of tobacco, precious jewels, and drugs, said the Central Asian News Service.
The news agency said Ayombekov refused to surrender to police and instigated the attack against government forces.
Tajikistan gained independence with the collapse of the Soviet Union in 1991 but has been troubled ever since by bloody war, widespread corruption and poverty.
Tensions remain high between the Tajik government in Dushanbe and the people of Gorno-Badakshan, who are of the Pamiri ethnic minority.
The region was a stronghold of Islamist rebels during a five-year civil war in the 1990s that claimed thousand of lives. The war also divided people along ethnic and regional lines, and the Pamiris, by and large, sided with the opposition.
A United Nations-brokered peace plan left President Emomali Rakhmon's secular government in place but gave some of his Islamist opponents official jobs.
But Rakhmon, backed by Moscow, has sought to consolidate power and stamp out remnants of radical Islam.
Khorog residents said they received no warning of Tuesday's fighting. People panicked as gunfire rang out.
Journalist Mirzojalol Shohjamolov said a group of residents gathered in front of Khorog Square, near the government building, with signs that said: "Stop military actions in Khorog."