ARUSHA, Tanzania — Tanzania on Saturday said Democratic Republic of Congo's M23 rebels must end threats over the country's planned sending of troops as part of a UN force to tackle the insurgents. Meanwhile, Thousands of people have fled the town of Pinga in eastern Congo following renewed fighting between local armed groups. “This is intimidation, they must stop it,” Tanzanian foreign minister Bernard Membe told parliament. “If they provoke us, we will retaliate.” Last month the M23 rebels, who operate in eastern DR Congo, warned they would retaliate if attacked by a new United Nations peacekeeping force, in which Tanzania are due to take a key role. M23's political leader Bertrand Bisimwa last month wrote to Tanzania's parliament warning the fighters had previously beaten even “larger and better equipped” forces, and that the same would happen to Tanzanian troops if they continued in this “dangerous adventure.” But Membe said Tanzania was not frightened. “Our army is very strong. We will be in DRC as a force for peace, to restore peace in the burning house of our neighbor,” he said, accusing the rebels of “killing, raping and forcing several thousand people to flee.” M23, named for a peace deal with the DRC government signed on March 23, 2009, emerged out of an ethnic Tutsi mutiny in the army in April 2012, on the grounds that Kinshasa was not upholding the pact. The rebels briefly seized the North Kivu provincial capital Goma in November last year. In March, the UN Security Council unanimously approved the creation of a brigade of more than 2,500 troops with a mandate to conduct “targeted offensive operations” against rebels in eastern DR Congo, a mineral-rich area that has been gripped by conflict for more than two decades. The UN force is due to consist of three infantry battalions, an artillery company, a reconnaissance company and “special forces,” with troops being mustered from South Africa, Malawi and Tanzania. As the fighting persists in eastern Congo, most of the population has fled into the nearby forest, while some civilians have taken refuge in the town's hospital. Doctors Without Borders initially said that 11 members of its Congolese staff had gone missing, but two staff members have since been accounted for. Jan Peter Stellema, the head of Doctors Without Borders' operations in Goma, said the aid group expected to hear from the others soon. Fighting against the M23 has mobilized most of the Congolese army resources for a year, creating a security vacuum in large areas of Congo's North Kivu province. Both the Congolese army and the M23 have forged alliances with local armed groups to extend the areas under their control. The APCLS has been armed by the Congolese army, while Mai Mai Checka is believed to be an ally of the M23. Caught in the middle are civilians in Pinga, some of whom have been accused of collaborating with one or the other militia. Residents say they have suffered murders, rapes and pillaging amid the fighting. In September, Mai Mai Checka decapitated several civilians and paraded the heads around the town to intimidate the population. Following Sunday's fighting, several houses were pillaged and one combatant was beheaded, Doctors Without Borders said.— Agencies