Can I run two 4k (3840x2160) displays at 60hz on a Macbook Pro 13" 2015 I think the title says it all. Can I run two 4k (3840x2160) displays, both at 60hz on a Macbook Pro 13' 2015? I understand they might need to be SST and each connected to a Thunderbolt 2 port. But I cannot get a confirmation whether that setup would work. 

https://support.apple.com/kb/SP719?locale=en_US says:


  Simultaneously supports full native resolution on the built-in display and up to 3840 by 2160 pixels on up to two external displays, both at millions of colors.
  …
  Support for up to 5120-by-2880 resolution at 60Hz on a single external display (model with AMD Radeon R9 M370X only)


Unfortunately, it does not state at what frequency the two displays can be run. 

https://support.apple.com/en-us/HT206587 says:


  With OS X Yosemite v10.10.3 and later, most single-stream 4K (3840x2160) > displays are supported at 60Hz operation on the following Mac computers: … MacBook Pro (Retina, 13-inch, Early 2015) and later. MacBook Pro (Retina, 15-inch, Mid 2014) and later


Unfortunately it does not state whether two displays can be run at 3840 by 2160 at 60hz
Assuming that you are using an Early 2015 MacBook Pro 13", it uses the Intel Iris 6100 chip.

From the review of the Intel Iris 6100 by NotebookCheck:


  All Broadwell GPUs support OpenCL 2.0 and DirectX 12 (FL 11_1). The video engine can now decode H.265 using both fixed function hardware as well as available GPU shaders. Up to three displays can be connected via DP 1.2/eDP 1.3 (max. 3840 x 2160 @ 60 Hz) or HDMI 1.4a (max. 3840 x 2160 @ 24 Hz). HDMI 2.0, however, is not supported.


The capability is there to support up to 3 displays with a max resolution of 3840x2160 @ 60Hz.

You connect it via mDP (mini Display Port) through the Thunderbolt 2 port.