I also read Sura Fateh at graves. Some pray to the dead asking them to intercede on their behalf with God. Asking a dead saint to talk to God about their problems. That is worshipping the grave. Dead are dead and pray to God only.
About this matter is two kind of Ayyeh in Qurran ...
1- in first kind of Ayyeh , Allah reject any intercession
يَا أَيُّهَا الَّذِينَ آمَنُوا أَنفِقُوا مِمَّا رَزَقْنَاكُم مِّن قَبْلِ أَن يَأْتِيَ يَوْمٌ لَّا بَيْعٌ فِيهِ وَلَا خُلَّةٌ وَلَا شَفَاعَةٌ ۗ وَالْكَافِرُونَ هُمُ الظَّالِمُونَ
بقره -254
254. O you who believe! Spend of that with which We have provided for you, before a Day comes when there will be no bargaining, nor friendship, nor intercession. And it is the disbelievers who are the
Zalimun (wrong-doers, etc.).
2- in second kind of Ayyeh in Qurran , Allah gave permission to some Holy and innocent people to ask forgiveness for some other people
يَوْمَئِذٍ لَّا تَنفَعُ الشَّفَاعَةُ إِلَّا مَنْ أَذِنَ لَهُ الرَّحْمَـٰنُ وَرَضِيَ لَهُ قَوْلًا
طه - 109
109. On that day no intercession shall avail, except the one for whom the Most Beneficent (Allah) has given permission and whose word is acceptable to Him.
وَلَا يَمْلِكُ الَّذِينَ يَدْعُونَ مِن دُونِهِ الشَّفَاعَةَ إِلَّا مَن شَهِدَ بِالْحَقِّ وَهُمْ يَعْلَمُونَ
الزخرف - 86
86. And those whom they invoke instead of Him have no power of intercession; except those who bear witness to the truth (i.e. believed in the Oneness of Allah, and obeyed His Orders), and they know (the facts about the Oneness of Allah) .
translate are from :
Noble Quran.com - Islamic Audio Recitation of the Quran in Mp3
as you see in first kind of Ayyeh , Allah reject any kind of "intercession" but in second kind of Ayyehs , Allah just made some exception and he saying that some people have permission to "intercession" for others ...
our scholar interpreter this matter like this : " generally , intercession in judgment day is forbidden but Allah is merciful and that why he gave
his permission to some and innocent people like Prophets , Imams and some innocent and holy humans to ask forgiveness for some worthy humans being . in the end it is Allah who has right to show mercy and forgive them or just doesn't forgive them . Allah just want to give another chance to his subjects to be forgiven because he is ارحم الراحمین , Allah love his creatures and want them to go to heaven ... "
and there are so many condition to this :
1- they should believe that Allah is the only one who has to forgive them ...
1- those person should ask for forgiveness in their life from Allah ( توبه / contrition )
2- they shouldn't repeat their sins
3- be believer and see Allah as sole owner of all of worlds
4- always read their daily prayer ...
5- don't commit Great Sins ....
6- and etc ...
there are so many conditions but I'm not expert in this field and just have some minor study to solve this doubt / َشبهه for myself ...
I should admit that this concept is really dangerous for people are not familiar with it or just using it to fool themselves and other naive and ignorant people ....
I saw and are seeing some idiots who are committing sins after sins and when someone is warn them to stop committing sins and ask for forgiveness for Allah , they say " We will go to grave of our Imam and ask for forgiveness and they will forgive us " ; they are wrong and they will face wrath of Allah in judgment day ; as far as I remember , some of our Imams cursed this kind of humans and said something like this "Imams don't have permission to ask for forgiveness for this kind of guys and even if they had , they wouldn't ask such things from Allah because Allah is absolute justice and he wouldn't forgive this kind of humans ..." .
so in the end of they , Allah is the one who has to forgive people ...