Colombian troops advance on scene of fighter plane crash in rebel area The wreckage of the military aircraft that crashed in Cauca province, Colombia. Photograph: Jaime Saldarriaga/Reuters Colombian forces are trying to reach the site where a fighter plane went down this week, amid some of the most intense sustained fighting between leftist rebels and government troops in years. Revolutionary Armed Forces of Colombia (Farc) rebels claim they shot down the Super Tucano fighter plane on Wednesday in Cauca province, one of the main fronts in Colombia's four-decade-old civil war. Government officials cast doubt on the claim, saying it was probably a mechanical failure. On Thursday the Farc handed over the body of one of the pilots to the International Committee of the Red Cross, which later recovered the remains of the second from the crash site. Troops have advanced slowly towards the area, which military officials say has been planted with landmines. The plane went down on the same day the president, Juan Manuel Santos, visited the town of Toribío, Cauca, which has been under virtual siege by the Farc for more than week. There have been attacks on the police station, civilian homes and a small hospital, and on nearby towns such as Jambaló and Argelia, where a motorcycle bomb killed a nine-year-old boy. Santos's visit may have intensified rather than calmed the situation, with the military fending off sporadic guerrilla fire as he held a cabinet meeting in the town centre. The president was greeted with jeers from townspeople and the Nasa indigenous community, who are demanding a withdrawal of the police and army which they say only attract the guerrilla attacks. Santos said he would not pull troops out. "Our military and police are here to protect you," he said. They are here and they're going to stay. Luis Eduardo Celis, a conflict analyst with the Nuevo Arco Iris thinktank, said the fight in Cauca, a largely rural province in the south-west where towns are tucked into high mountain valleys, was not just over territory. It also concerned control of drug crops, trafficking routes to the Pacific and gold deposits, he said. The province is historically a rebel stronghold and the Farc maintain significant logistical support from a network of non-uniformed members and some civilians. Military intelligence estimates the Farc has 9,400 armed fighters nationwide and an equal number of non-uniformed support troops, or milicianos. The Farc made the decision a few years ago to make Cauca one of their main battlegrounds because that's where they can. That's their territory," Celis said. But the army has also resolved to take control of the province, sending additional troops to the region since February as part of a new strategy called Sword of Honour.