What is the ruling regarding Imsak before the Fajr? Is it Haram to eat or drink after the Imsak?

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Know, dear brother, that fasting is from dawn to sunset. There is no time before dawn called "Imsak". What is found in some leaflets and diaries specifying a short time before the Fajr Adhan as the starting time of fasting is a precaution only. There is no evidence for this. In fact, it is contrary to the Sunnah. Indeed, it is lawful for us to eat, drink etc. from sunset to dawn. Whenever dawn appears, we start fasting and stop doing all things that are not allowed during fasting.
Allah knows best.