A new report by United Nations special investigators says Kenya's military was responsible for five attacks on telecommunications masts in neighbouring Somalia, including strikes that killed two civilians.The Kenya Defence Forces (KDF) attacked communications towers in Somalia between 2017 and 2019, in a possible effort to stop al-Shabaab using mobile signals to detonate bombs, an expert panel reported in its latest update to the UN Security Council on Monday.The panel, which monitors sanctions on Somalia, said it received reports of KDF attacks on 12 towers operated by Hormuud Telecom, a Mogadishu-based provider, since 2017, almost all in Gedo along Kenya's northernmost border with Somalia."The Panel has been able to independently corroborate five of those attacks... which resulted in the deaths of two civilians," the UN sanctions committee said. A security guard and his relative died in July 2018 in an alleged KDF shelling on a Hormuud station, the report added.The KDF denied any involvement in the attacks during a meeting with the UN experts, the report noted.The report did not give details of how all of the attacks were carried out, although it referred to shelling in one incident and to at least one air strike.Hormuud Telecom has alleged at least 12 attacks. In August, it said that one assault had not only destroyed a mast but also two power generators, batteries and a building.The findings come at a time of strained relations between Kenya and Somalia. The neighbours are sparring on several diplomatic fronts, including a battle over contested marine borders with possibly lucrative Indian Ocean oil and gas reserves at stake.Kenya sent troops into southern Somalia in 2011, joining the regional peacekeeping force Amisom that drove al-Shabaab from Mogadishu. It has justified the incursion to protect Kenyans from the al-Qaeda affiliate which, among other assaults, killed 21 people in Nairobi in January. It was also suspected of a roadside bombing in October that killed 11 Kenyan police officers near the Somali border.In its report, the UN panel recorded "an unprecedented number" of cross-border attacks into Kenya by the Islamist militants in June and July this year. These were possibly timed to worsen relations between the East African neighbours, it said.For the first time, investigators also found proof al-Shabaab had been making homemade bombs since at least July 2017, no longer relying on explosives leftover from Somalia's devastating civil war.The UN report acknowledged that KDF attacks on telecommunications equipment may "prevent al-Shabaab from triggering improvised explosive devices" using mobile networks. It also noted KDF complaints that its communications towers had also been attacked since 2015, largely by al-Shabaab."However, there are humanitarian implications to the long-term loss of telecommunications coverage within Somalia, including impeding the coordination of relief efforts, the transfer of food vouchers and the receipt of remittances from outside the country," it said.