RIYADH — A man who was arrested in connection with a series of arson attacks on school buses in Riyadh earlier this month is believed to have planned his operation for several months. The arsonist set ablaze 14 buses that were used to transport girl students in two locations and the suspect was arrested as he attempted to set alight vehicles at a third. The 37-year-old man was suspected of monitoring the locations of the buses, including one north of Riyadh and the second one east of Riyadh. Police said they started gathering leads when Civil Defense investigators pointed out that the fires were deliberate. Information was passed to police about the fire and officers started an investigation, leading to the suspect's arrest a few days after. The man had poured gasoline all over the buses and was getting ready to set them alight when officers arrested him, police said. Col. Naser Al-Qahtani, Riyadh police spokesman, said earlier this month police received two separate reports about bus fires from the Civil Defense. In the first incident eight buses were set on fire and in the second six were targeted, with a short interval between each attack. Police formed a task force and began investigations. A few days later officers started monitoring a man inside a 2010 silver Toyota Camry who was near a group of school buses. When police tried to stop him, he escaped from the scene. After a short chase, police surrounded the man and arrested him. Inside his car police found six bottles of gasoline and lighters. He was handed over to prosecution authorities for further investigations. When police searched his home, they found maps of Riyadh, a number of computers and gallons of gasoline.