Story highlights Donald Trump reacted to a series of bombings over the weekend with a warning that more attacks are likely

Trump also argued for stricter immigration policies and knocked "magazines" and "websites" that provide bomb-making instructions

(CNN) Donald Trump reacted to a series of bombing threats and attacks over the weekend with a warning on Monday that "this is only going to get worse."

"I think this is something that will maybe get -- will happen perhaps more and more all over the country," Trump told "Fox and Friends." "It's a mess, and it's a shame, and we're going to have to be very tough."

Trump also said he agreed with early reports of a possible foreign connection to the bombings.

"I think there is -- I think there's many foreign connections," he said.

"You have many, many groups, because we're allowing these people to come into our country and destroy our country and make it unsafe for people," the Republican nominee added, arguing that the stricter immigration policies he has proposed would better protect the US from terror.

Read More