Iraqi police have arrested two fugitive prisoners and found four others drowned out of a group of 14 who escaped from jail in the city of Mosul using a tunnel, a security official said on Sunday. Security forces on Sunday found two prisoners drowned in the Tigris river during their escape, said Abdulrahim al-Shammari, the Nineveh provincial council member responsible for defence and security. Police on Saturday found another escaped detainee from the prison in the northern city of Mosul, capital of Nineveh, who had also drowned, Shammari said. And on Friday, security forces arrested two fugitives and found one drowned, leaving eight prisoners still at large, he said. Colonel Mohammed al-Juburi of Nineveh police said on Thursday that 35 prisoners charged with terrorism-related offences had tried to escape that day, 14 of whom were successful. "The prisoners dug an 80-metre (yard) tunnel to reach the bank of the (Tigris) river," Nineveh operations chief Lieutenant General Hassan Karim said, adding the escapees had "received help from inside and outside the prison." Jailbreaks and prison unrest are not uncommon in Iraq. Officials said on August 6 that four prisoners and a guard were killed in clashes at a prison in the central city of Hilla during which eight inmates escaped. Six police and 11 inmates were killed in a Baghdad jail mutiny in May, while 12 suspected Al-Qaeda members escaped from prison in the southern city of Basra in mid-January. At least two of the Basra escapees have been recaptured.