Airlines in India will need to keep the middle seat empty if passenger load factors and seat capacity allow for it, the aviation regulator said in a notice to domestic and international carriers, Reuters reported.

However, members of the same family would be allowed to sit together, the Directorate General of Civil Aviation (DGCA) said in its notice.

The regulator did not elaborate on what load factors or seat capacity would require the middle seats to be left vacant. It said the rules would come into effect from June 3.