Can programming pins on AtTiny84a be connnected to LEDS while being programmed?

[buck converter]

So I want to use a Attiny84a-ssu to drive some leds. Can LEDS be connected to the programming pins (sck, mosi, miso) while being programmed?
I only need 5 leds, but i am etching single layer boards at home and it is for a REALLY tiny project. It would make the board layout much smaller if the programming pins were driving the LEDs.
I would be programming it with my UNO and the Arduino IDE.

[ataradov]

Yes, they can. I do it here https://github.com/ataradov/logic/blob/master/hardware/logic_probe_v2.pdf , for example.

[Mechatrommer]

yes you can as long as you have high impedance to the led or anything for that matter. (the high value resistor, such as R4 R5 R6 in Alex's diagram)