The government yesterday gave separatist rebels until June 1 to stop all attacks against civilians and reject all links with foreign terrorist groups. As the ultimatum against the Moro Islamic Liberation Front (MILF) was issued, Davao city mayor Rodrigo Duterte, the presidential adviser against crime, expressed fears that Mindanao in the southern Philippines was on the brink of a civil war. 'Events are unfolding fast and I tell you it's not a good one,' said the tough-talking mayor, whose city was recently bombed twice. 'You better watch out because the level of animosity' between Muslims and Christians was rising, he said. 'Once we cross that Rubicon, the die is cast. There's no turning back.' He suggested that peace talks be scrapped altogether in favour of an all-out military offensive against the MILF. As religious and civil leaders held a peace conference in Cotabato city yesterday and Muslims observed the birthday of the Prophet Mohammad, President Gloria Macapagal-Arroyo kept up the pressure on the rebels. 'The MILF must cut its double talk and make a clear statement on whether it's allied with the Abu Sayyaf and foreign terrorist groups such as Jemaah Islamiah or al-Qaeda, or unequivocally reject them,' she said. Otherwise, her spokesman Ignacio Bunye said, the government would have the MILF listed as a foreign terrorist organisation. This would result in its assets being frozen at home and abroad, he said. MILF spokesman Eid Kabalu dismissed the government ultimatum as unnecessary because he said the group had already disowned connections with Abu Sayyaf, al-Qaeda and Jemaah Islamiah. 'We even invited the government to investigate,' Mr Kabalu said.