If there are many travellers, Adhan and Iqama should be pronounced, (the same is to be observed) in 'Arafat and Al-Muzdalifa too
حَدَّثَنَا مُسَدَّدٌ، قَالَ أَخْبَرَنَا يَحْيَى، عَنْ عُبَيْدِ اللَّهِ بْنِ عُمَرَ، قَالَ حَدَّثَنِي نَافِعٌ، قَالَ أَذَّنَ ابْنُ عُمَرَ فِي لَيْلَةٍ بَارِدَةٍ بِضَجْنَانَ ثُمَّ قَالَ صَلُّوا فِي رِحَالِكُمْ، فَأَخْبَرَنَا أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يَأْمُرُ مُؤَذِّنًا يُؤَذِّنُ، ثُمَّ يَقُولُ عَلَى إِثْرِهِ، أَلاَ صَلُّوا فِي الرِّحَالِ. فِي اللَّيْلَةِ الْبَارِدَةِ أَوِ الْمَطِيرَةِ فِي السَّفَرِ.
Narrated Nafi`: Once in a cold night, Ibn `Umar pronounced the Adhan for the prayer at Dajnan (the name of a mountain) and then said, "Pray at your homes", and informed us that Allah's Messenger (ﷺ) used to tell the Mu'adh-dhin to pronounce Adhan and say, "Pray at your homes" at the end of the Adhan on a rainy or a very cold night during the journey."