The Hague - International Criminal Court chief prosecutor Fatou Bensouda warned on Friday against spiralling violence in the volatile Democratic Republic of Congo, saying her office was "carefully monitoring" the situation."I am deeply concerned by the numerous reports over the past several months of serious acts of violence in the DRC, particularly in the Kasai province," Bensouda said in a statement issued in The Hague.The remote central province of Kasai has been plagued by violence since mid-August, when government forces killed Kamwina Nsapu, a tribal chief and militia leader who had rebelled against President Joseph Kabila's central government."I shall not hesitate to take action if acts constituting crimes within the jurisdiction of the court are committed and to take all necessary measures to prosecute those responsible," she said.The violence has spilled over from Kasai to the neighbouring provinces of Kasai-Oriental and Lomami, leaving at least 400 people dead.The bodies of two foreign UN contractors, American Michael Sharp and Swedish national Zaida Catalan, who were kidnapped in the region earlier this month, were discovered this week. One of the bodies was decapitated.Four Congolese nationals who were accompanying them are still missing. Diplomats at the UN told AFP that the murdered pair had been investigating reports of mass graves.Last week, 39 police were killed in an ambush by rebels in Kasai.Bensouda's warning came just hours before the UN Security Council was to vote to cut by 3 600 the 20 000 troops in its peacekeeping mission in country.Bensouda called on all parties to "refrain from recurring to criminal violence" while calling on the Congolese government to bring the perpetrators to justice in the volatile central African country.The ICC, set up in 2002 to probe and prosecute the world's worst crimes, has been investigating war crimes and crimes against humanity in the DRC since June 2004.These investigations have led to the ICC's first two convictions.Warlord Thomas Lubanga was sentenced to 14 years for using children in his rebel army, while Germain Katanga was handed a 12-year sentence for an ethnic attack in 2003 on a village in the war-torn northeast Ituri province.A third trial, that of Bosco Ntaganda, is still ongoing.Ntaganda has denied 18 charges of war crimes and crimes against humanity. But prosecutors say he played a central role in the Ituri conflict which rights groups believe has left some 60 000 dead since 1999.