The Muslims also consider Guru Nanak a prophet, I have come across a Janam Sakhi which states the Guru performed a miracle at Mecca, one which is also stated by the Qu'ran. The Janam Sakhi is in english, and written below:
....The fourth journey took Guru Nanak westwards to Mecca, evidently without a regular companion. For this journey he wore leather shoes, pajama, a blue garment, and a necklace of bones. Having reached his destination he went to sleep with his feet in the direction of Mecca and a qazi named Rukandin who happenned to observe him in this position , rebuked him severely. The Guru suggested that the qazi should drag his feet round and leave them pointing in a direction away from God and the Ka'bah. Rukandin complied and was amazed to discover that as he moved the Guru's feet the
miharab moved with them. He summoned Pir Patalia and the three engaged in discourse. At its conclusion Guru Nanak uttered 'Vahiguru' and water appeared in the wells, thus fulfilling a prophecy contained in the Muslim scriptures that Nanak , a
darves, would come and cause water to spring in the wells of Mecca.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/islam/14692-islam-view-on-sikhism-please-help.htmlReference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=14692
Source:
-- 'Guru Nanak and the Sikh Religion' by W. H. McLeod
For a Muslim to disrespect or insult a Sikh, is an insult to a prophet recognised by there people. Some need to be reminded of this.