Britain's Coastguard says it has helped Border Force officers respond to reports of boats carrying migrants off the southeastern coast.

The number of migrants detained Saturday was not immediately clear. Coastguard officials, however, said 13 incidents had been reported, stretching from the port of Dover to Winchelsea Beach near Hastings, 50 miles (80 kilometers) away. Saturday saw exceptionally warm sunny weather in southern Britain.

Local lawmaker Charlie Elphicke demanded in a tweet that the "Home Office needs to get a grip on this crisis."

The reports about migrants coming into the U.K. using small boats to cross the English Channel are politically volatile. Last year Home Secretary Sajid Javid declared a rise in migrant crossings to be a "major incident."

Officials have blamed the influx on smuggling gangs.