Three Senate Democrats sent a letter to Amazon urging the company to do something about the thousands of unsafe or banned products listed on the e-commerce site.

In a letter sent to Amazon CEO Jeff Bezos on Thursday, Sen. Richard Blumenthal, D-Conn., Sen. Bob Menendez, D-N.J., and Sen. Ed Markey, D-Mass., asked him to take action to stop the sale of unsafe products on Amazon. The senators also called on Bezos to put in place more accurate warnings on products that require them.

The letter was in response to a recent Wall Street Journal investigation, which found more than 4,000 items for sale on Amazon’s site that have been declared unsafe by federal agencies, have misleading labels or are outright banned by federal regulators. Following the report, Amazon removed or changed the description on more than half of the problematic listings, according to the Journal.

But the senators said more could be done to clean up unsafe products on Amazon.

“Unquestionably, Amazon is falling short of is commitment to keeping safe those consumers who use its massive platform,” the senators wrote in the letter. “We call on you to immediately remove from the platform all the problematic products examined in the recent WSJ report; explain how you are going about this process; conduct a sweeping internal investigation of your enforcement and consumer safety policies; and institute changes that will continue to keep unsafe products off your platform.”

The senators included a number of questions for Bezos seeking more information on Amazon’s safety efforts and policy enforcement, with a deadline for Bezos to respond by Sept. 29. Blumenthal told the Journal that he intends to seek congressional hearings once Bezos responds to the letter and said federal agencies should probe whether Amazon violated federal consumer protection laws.

An Amazon spokesperson said the company plans to respond to the letter of inquiry and pointed to a statement that it posted in response to the Journal investigation. In the blog post, Amazon said it requires products on its site to comply with “relevant laws and regulations” and pointed to its use of automated tools to detect noncompliant products.

The letter represents the latest example of Amazon facing pressure from Washington. Earlier this month, Blumenthal and Menendez sent a letter to Bezos asking for answers about the company’s “Amazon’s Choice” badge, citing a BuzzFeed report that showed it often endorses defective or poor quality items.