He assumed Ihram as a Mufrid (for Hajj only) with a group, then they went to Al-Madinah, so what should he do?
Question :
I came with a group for Hajj and I assumed Ihram as a Mufrid (for Hajj only). Then my group wanted to travel to Al-Madinah. Can I go to Al-Madinah and return to Makkah to perform "Umrah after a few days?
Answer:
If the person performs Hajj with a group and he assumes Ihram for Hajj as a Mufrid, then he travels with them to visit the Prophet's Mosque, it is legislated for him to make his Ihram for 'Umrah, make Tawaf and Sa'y for it, get his hair cut and remove his Ihram. Then he assumes Ihram for Hajj during its time (i.e., the 8th of Thul-Hijjah) and with that he becomes a Mutamatti'. He must sacrifice an animal for At-Tamattu' as the Prophet ordered his Companions to do, who did not have sacrificial animals with them.
Source:
Ash-Shaykh Ibn Baz
Fatawa Islamiyah, Vol. 4 Pages 99-100