Question:

They perform their prayers without the Adhan; what is the ruling?

​Answer:

It is not permissible for them to perform their prayers without an Adhan, because the Adhan is a ‘communal obligation’ (Fard Kifayah) upon the Muslims in every town.

Similarly, travelers are required to give the Adhan for prayer, just as the Prophet (peace and blessings be upon him) used to do during his travels, and as established from him (peace and blessings be upon him) when he said to Malik ibn al-Huwayrith and his companions—when they asked permission to return to their people: “When the time for prayer arrives, let one of you give the Adhan for you, and let the eldest of you lead you in prayer.” This is agreed upon as authentic.​Therefore, if the residents of a town abandon it, all of them incur sin.

Furthermore, when the Prophet (peace and blessings be upon him) intended to launch a raid against a people, he would wait until morning; if he heard an Adhan, he would hold back from them, and if not, he would attack them. However, the Adhan is not a condition for the validity of the prayer; thus, if they pray without an Adhan, their prayer is valid.

And Allah is the Grantor of success. May Allah send blessings and peace upon our Prophet Muhammad, his family, and his companions.