CAIRO - In a room in eastern Cairo on the campus of Al Azhar University is a room filled with about 50 computers.
Here, religious scholars do battle with terrorists, fighting them not with guns, but with words and theology.
This is the Al Azhar Observatory for Foreign Languages, which monitors extremist ideology online, trawling through websites and social media in nine different languages - including English, Mandarin and Urdu - before publishing rebuttals of their own.
It is one of Egypt's key institutions that help it combat religious extremism in the country and beyond. On Monday afternoon (Oct 31), President Tony Tan Keng Yam met Al Azhar Grand Imam Ahmed Al Tayyeb, and toured the observatory
Al Azhar, one of the oldest universities in the world, is a top destination for Singaporeans pursuing Islamic studies.
Dr Tan, who is on his first state visit to Egypt, met Dr Al Tayyeb before the tour, where they discussed how both countries can promote religious tolerance and understanding.
The observatory was set up in 2015 by Dr Al Tayyeb, a key Egyptian figure who has called for tolerance in a region fractured by religious differences.
Dr Al Tayyeb has been travelling the world meeting and building bridges with leaders of other religions - including Pope Francis, whom he met in May (2016) - said his consultant for foreign relations, Mr Abdel Rahman Moussa.
He added that battling extremism is the Grand Imam's "main concern", and the observatory was set up to counter efforts by terrorist groups such as the Islamic State in Iraq and Syria (ISIS) to use social media to radicalise converts.
"We decided quickly to establish this observatory... to answer and refute all these allegations and thoughts of the terrorist groups, which spread all over the world," said Mr Moussa.
The battle can be fierce, some terror groups can issue thousands of erroneous messages a day - ISIS for instance can send between 4,000 to 7,000 rulings to its followers all around the world daily, said Mr Moussa.
Religious scholars at the observatory find these messages, analyse them and respond immediately online on the same social media platforms using Islamic law and theology, he added.
They do so "in order to refute these ideas and to explain to youths the proper thoughts and ideas, and how all these allegations... are false, and don't have any connection with Islam, Muslims and the Islamic cause".
For instance, one common misconception is the idea that Muslims must establish and live in an Islamic State, or caliphate - the raison d'etre of ISIS.
"There is no Islamic state in Islam at all... we are refuting all these ideas at the moment," said Mr Moussa.
Earlier on Monday, Dr Tan also called on Egyptian President Abdel Fattah al-Sisi.
On Tuesday (Nov 1), he is scheduled to meet Egyptian Prime Minister Sherif Ismail in the morning, before attending a special graduation ceremony for 45 Singaporean Al Azhar students in the evening.