Alexander Gerst rockets israel gaza
Alexander Gerst shared an image believed to show rocket fire between Israel and Gaza.Alexander Gerst/Twitter

An astronaut on board the International Space Station has shared his "saddest" ever image from space – a photo showing rockets and explosions in Israel and Gaza.

Alexander Gerst posted the picture on Twitter with the caption: "My saddest photo yet. From ISS we can actually see explosions and rockets flying over Gaza & Israel."

The ISS was stationed about 200 miles above the Earth as it passed over Israel and Gaza.

Rockets can apparently be seen shooting between the two areas – although Nasa told Mashable it needs to verify what is shown in the photo.

Gerst, from Germany, was assigned to join the ISS in September 2011. He set off from the Baikonur Cosmodrome in Kazakhstan on a Soyuz spacecraft in May 2014. He will return to Earth in November.

His photo comes as the UN warned that Israel may have committed war crimes in its attack against Hamas in Gaza. "There seems to be a strong possibility that international law has been violated, in a manner that could amount to war crimes," Navi Pillay, the UN high commissioner for human rights, said.

The conflict has been going on for over two weeks and so far over 700 people have been killed – more than 690 Palestinians, including at least 160 children, and 34 Israelis.