Looks like those reports of Hamas fighters streaming into Egypt were accurate.

Via Times of Israel:

The Egyptian army has killed some 200 gunmen in Sinai, including 32 Hamas members, and arrested 45 others over the past several days, an Egyptian security source told London-based Arab daily Al-Hayat on Thursday.

The unnamed official accused Hamas of intentionally escalating the security situation in Sinai following the ouster of president Mohammed Morsi. The official claimed that Egyptian military forces have observed Hamas activists operating in Sinai in cooperation with local jihadists.

“The army is barely in control of the situation,” the official told the daily. “They enter Sinai through the tunnels to carry out attacks together with others and return to Gaza through the tunnels. Moreover, they exploit the terrain and hide in the mountains.”

Hamas, for its part, tried to distance itself from the developments in Egypt, claiming it has adopted a policy of non-intervention following the overthrow of Morsi.

“The intervention of Gazans in the Egyptian issue is nothing more than popular solidarity with the deposed president Mohammed Morsi, in whose time the situation improved on all levels,” read an article in Hamas news site Al-Resalah.