Yahoo has joined the increasing number of technology companies publishing details of how many requests US law enforcement agencies have made for data on their users.

The company gave more details of its dealings with US authorities as it sought to reassure customers in the wake of the scandal surrounding the National Security Agency's Prism surveillance programme.

A blogpost co-signed by Yahoo's chief executive, Marissa Mayer, and general counsel, Ron Bell covers the same period as Apple's disclosure earlier in the week: 1 December 2012 to 31 May 2013.

"During that time period, we received between 12,000 and 13,000 requests, inclusive of criminal, Foreign Intelligence Surveillance Act (FISA), and other requests," they wrote. "The most common of these requests concerned fraud, homicides, kidnappings, and other criminal investigations."

Mayer and Bell stated that they were legally unable to publish details of request numbers under the FISA. "We strongly urge the federal government to reconsider its stance on this issue," they wrote, before outlining plans for more transparency about the data Yahoo shares with law enforcement agencies.

"Democracy demands accountability. Recognising the important role that Yahoo! can play in ensuring accountability, we will issue later this summer our first global law enforcement transparency report, which will cover the first half of the year. We will refresh this report with current statistics twice a year."

Yahoo's disclosure of US requests between 1 December 2012 and 31 May 2013 can be compared directly with that of Apple, which said on Monday that it received between 4,000 and 5,000 requests from federal, state and local authorities in that time period.

Facebook and Microsoft's disclosures covered a different period: the second half of 2012. Facebook said it received between 9,000 and 10,000 requests in that six-month period, while Microsoft said it received between 6,000 and 7,000.

All the companies are fighting hard to regain any trust lost with their users since the Guardian broke the news of the NSA's Prism programme. Their initial public responses focused on denying all knowledge of any programme giving the NSA direct access to their servers.

In recent days, their strategy has shifted to espousing transparency by publishing their US request figures, while seeking to stress that they push back against requests they see as inappropriate.

When Facebook's published its requests data, the general counsel, Ted Ullyot, wrote: "We aggressively protect our users' data when confronted with such requests: we frequently reject such requests outright, or require the government to substantially scale down its requests, or simply give the government much less data than it has requested".

Apple's statement said: "Regardless of the circumstances, our legal team conducts an evaluation of each request and, only if appropriate, we retrieve and deliver the narrowest possible set of information to the authorities. In fact, from time to time when we see inconsistencies or inaccuracies in a request, we will refuse to fulfill it."

Yahoo's statement falls into that pattern too. "As always, we will continually evaluate whether further actions can be taken to protect the privacy of our users and our ability to defend it," write Mayer and Bell. "We appreciate – and do not take for granted – the trust you place in us."