CAIRO (Reuters) - An Egyptian military court on Wednesday sentenced five Palestinian fishermen to a year in jail for illegally crossing into Egypt’s territorial waters, Egyptian security sources said.

“The court had arrested five Palestinians recently for crossing without permits to the Egyptian waters in North Sinai (that borders Israel and the Palestinian Gaza enclave),” one security source said. The source said each of the fishermen was also fined 500 Egyptian pounds ($72.53).

It was not clear when the incident took place, according to another security source in Sinai.

The event comes at a sensitive time after the Egyptian army ousted Islamist President Mohamed Mursi last July. Hamas, the Islamist group that controls the Gaza Strip, is an offshoot of Mursi’s Muslim Brotherhood group.

The relationship between Egypt’s army-led authorities and Hamas deteriorated sharply this month after Egypt escalated a crackdown on cross-border smuggling tunnels between its volatile Sinai desert and Gaza.

Egypt’s state media this month accused Hamas of being involved in training Islamists in Egypt how to plant bombs and that it had given them landmines - an accusation dismissed by the Palestinian group as an attempt to demonize it.

Egypt is carrying out a military operation against Islamist militants in Sinai, which has experienced a security vacuum since the fall of autocratic Egyptian President Hosni Mubarak after an uprising in 2011.

($1 = 6.8933 Egyptian pounds)

(This version of the story was refiled to fix currency conversion.)