FBI sees spike in threat tips following El Paso, Dayton mass shootings More than 38,000 people called the FBI tipline in the first week of August.

The FBI said Monday it has seen a significant surge in the number of calls to its threat tip line following the El Paso and Dayton mass shootings earlier this month, a bureau official told ABC News Monday.

"In the first week in August, the FBI saw an increase in tips submitted to the National Threat Operations Center," the FBI said in a statement. "Such increases are often observed after major incidents."

On average, the official said, the FBI receives approximately 22,000 tip calls per week to the NTOC.

In the weeks following the El Paso and Dayton shootings, that number has been up by 10-15,000 tip calls each week.

In the first week of August alone, the official said, the FBI received more than 38,000 tip calls to the NTOC.

The official noted that not all of the tips the FBI receives are actionable, and said the bureau was not able to provide a breakdown of how many tips turn into FBI investigations.

"What that number does show is that people are calling the FBI more, especially during that first week," the official said.

According to an analysis by ABC News last week, at least 14 individuals were arrested in a 20-day span following the El Paso and Dayton shootings who local, state or federal law enforcement have said were plotting or expressing interest in carrying out mass attacks.

While only a few were found to have expressed a direct interest in the El Paso or Dayton shooters, the arrests indicate that law enforcement is taking a much more aggressive posture in addressing online threats and tips relayed to them regarding possible mass shootings. According to court filings reviewed by ABC News, several of the suspects arrested were under investigation by law enforcement prior to this month's mass shootings.

"As always, the FBI encourages the public to remain vigilant and report any and all suspicious activity to law enforcement immediately," the bureau said in a statement. "Tips pertaining to violations of federal law or threats to national security can be submitted to the FBI by calling local Field Offices or 1-800-Call-FBI, or online at www.tips.fbi.gov."