Bismillhi Rahmani Raheem
Allahumma Swalli Ala sayyidina Muhammadin wa Ala Aali Sayyidina Muhammadin Wa Sallim
Prophet alaihiswalathu wasalam was asked by companions to curse the disbelievers. Prophet alaihiswalathu wa salam replied: “I have been sent as a Mercy to the world, not as a curse!
You see those who attack ahlul bayt and awliya Allah, they are cursing people of other faiths, in streets and demonstrations!
and you must know that they nether love Prophet alaihiswalathu wa salam, nor give any respect for Prophet’s words.
Islam does not teach to curse individuals, but the curse have been said as:
Curse of Allah up on liars ,Hypocrites, disbelievers etc, which God has cursed them in Quran. Not everyone authorized to cruse.
In some verses it has been said: the curse of all mankind on them
That is a natural and divine decree, curse are not fabricated but are originated from the soul!
the greatest punishment is not a sickness or wound or some worldly disasters!, losing Iman (faith) and die in the state of disbelief is the greatest punishment from Allah. And it has been narrated that, those who have malice against ahlul bayt (the progeny of beloved Prophet alaihiswalathu wa salam) will reach hell fire, regardless of his prayers,fasting and zakat, even if he did all that in his entire life between Stone and Station of Ibraheem (Maqam Ibraheem alaihissalam)
Imam Ahmad; Tirmidhi who denoted it sahih; Nisa’i and Haakim narrated it from Muttalib bin Rabee’a that the beloved Prophet SallAllaho Alaihi wa ala Aalihi wa Sahbihi wa Baaraka wa Sallam said to Sayyiduna Abbas Radi Allahu Ta’ala Anhu
والله لا يدخل قلب امرئ مسلم إيمان، حتى يحبكم لله ولقرابتي
‘By Allah, Imaan (faith) will not enter the heart of a Muslim until he loves you for Allah and for my relationship.’ [Musnad Ahmad, Vol. 1, Page 342, Hadith 1780 | Sunan Tirmidhi, Vol. 5, Page 610, Hadith 3758 | Sunan Nisa’i, Vol. 5, Page 51, Hadith 8175 | Mustadrak al-Hakim, Vol. 4, Page 85, Hadith 6960]
Tirmidhi, denoting it Hasan, and Tabarani narrated from Ibn Abbas the the beloved Prophet SallAllaho Alaihi wa ala Aalihi wa Sahbihi wa Baaraka wa Sallam said
أحبوا الله لم يغذوكم به من نعمه وأحبوني لحب الله وأحبوا أهل بيتي لحبي
‘Love Allah because of what He gave you from His blessings; Love me because of the Love of Allah and Love my Ahl al-Bait because of my Love.’ [Sunan Tirmidhi, Vol. 5, Page 622, Hadith 3789 | Mustadrak al-Hakim, Vol. 3, Page 162, Hadith 4716 | Tabarani in Al-Kabir, Vol. 3, Page 46, Hadith 2638 | Bayhaqi in Shau’ab al-Iman, Vol. 2, Page 13, Hadith 1378]
Tabarani and Haakim narrated from Ibn Abbaas that the beloved Prophet SallAllaho Alaihi wa ala Aalihi wa Sahbihi wa Baaraka wa Sallam said
يا ابن عبد المطلب: اني سالت الله لكم تلاثاً ان يثبت قلوبكم وان يعلم جاهلكم ويهدي ضالكم وسالته ان يجعلكم جودآء نجدآء رحمآء فلو ان رجلاً صفن بين الركن والمقام فصلى وصام ثم مات وهو مبغض لاهل بيت محمد دخل النار
‘O Children of Abdul Muttalib, I asked Allah three things for you; that He keeps your hearts steadfast (upon Islam); that He teaches the Deen to your ignorant and illiterate and guides your astray, and that He make you kind, generous and affectionate to one another. So if a man prays, standing between the Rukn and Maqaam, and fasts but dies with malice for the Household of Muhammad he has entered Hell.’ [Tabarani in Al-Kabir, Vol. 11, Page 142, Hadith 11412 | Mustadrak al-Hakim, Vol. 3, Page 162, Hadith 4712]
This hadith are copied from another article for your proofs