A rebel leader accused of orchestrating deadly attacks in Rwanda's border regions pleaded guilty on Thursday to terrorism and other charges, and admitted to working with foreign governments against Kigali.The admission of conspiracy by Callixte Nsabimana, the spokesperson for the National Liberation Front (FLN), risks further escalating tensions between Rwanda's President Paul Kagame and his immediate neighbours, whom he has accused of spying.Nsabimana was arrested last month for his involvement with FLN, an insurgent movement blamed for attacks inside Rwanda from a forested area near Burundi and the Democratic Republic of Congo.Nsabimana plead guilty to 16 charges including terrorism and murder, and offered an unconditional apology for his crimes."I apologise for all things I did," he told the court."I want to declare that my work with FLN is over, and anything else they do from now on is their business, not mine. I would like to apologise to the president, those that we injured and the families of those who died. I apologise to all Rwandans."His lawyer requested bail, with a hearing scheduled for Tuesday. The prosecution opposed bail, declaring Nsabimana a flight risk.KEEP UPDATED on the latest news by subscribing to our FREE newsletter.- FOLLOW News24 on TwitterIn December last year, Nsabimana claimed responsibility for setting fire to passenger buses in Nyungwe Forest - a region popular among tourists coming to see endangered mountain gorillas - which led to the death of two people and many injuries.Those attacks prompted many Western governments including France, Germany, Canada, and Australia to advise their nationals against travel to the area.A number of rebel groups opposed to Kagame - who has ruled for decades and pursued his political opponents at home and abroad - have proliferated just over Rwanda's borders in remote forest regions of DR Congo and Burundi.In his guilty plea, Nsabimana admitted to collaborating with Burundi's intelligence services and Uganda's military."We asked them for military and diplomatic support against Rwanda, and they were willing to help us," he said.Kagame has accused his neighbours of meddling in Rwanda's affairs and sponsoring armed movements against his government in Kigali. In February, he ordered the border with Uganda shut, and ties with Burundi have long been sour.The FLN is the armed wing of the Rwandan Movement for Democratic Change, a political opposition group founded by Paul Rusesabagina, the hotelier whose actions during the 1994 genocide were depicted in the Hollywood blockbuster Hotel Rwanda.Rusesabagina, in a video posted to YouTube in December, said the FLN was seeking to "liberate" Rwanda from an oppressive government in Kigali."Many Rwandans are taken by security forces and are never seen again," said Rusesabagina, who has lived in Belgium since the Rwandan genocide in 1994.The FLN is also affiliated with the Democratic Liberation Forces of Rwanda (FDLR), another rebel group based in DRC, which occasionally carries out cross-border attacks against Rwandan forces.