Two unusual additions to Gaza's ballooning population have been proudly announced by Hamas: twin lion cubs, the first to be born inside the beleaguered coastal strip.

Their arrival at the Bissan amusement park, a Hamas-run enterprise in Beit Lahiya, northern Gaza, came in the week of the anniversary of last year's eight-day conflict with Israel. To mark the timing, the cubs – one male, one female – were named Fajr and Sijil.

Fajr is Arabic for dawn, but is also the name of some of the missiles fired by Hamas and other militant groups at Israel last November. Sijil translates as clay, and is the name Hamas gave to last year's conflict.

The cubs' parents were smuggled into Gaza through the tunnels under the border with Egypt four years ago.

"The lioness gave birth yesterday [Monday] to two cubs, one male and one female," said Nahed al-Majdub, Bissan's manager, on Tuesday. "It is the first time lions have been born in the Gaza Strip," he added.

The cubs now face a life of captivity within captivity. Animals are kept in cages next to picnic areas. Bissan is one of several zoos in Gaza, most of which are populated with animals brought through smuggling tunnels.

Around the time of the cubs' birth, a woman from Gaza gave birth to sextuplets following fertility treatment. Ghada Hammad, 34, delivered four boys and two girls at a hospital in the West Bank town of Nablus.

Meanwhile, the Israeli military struck four targets in Gaza on Tuesday night, following rocket fire earlier in the day.

There has been sporadic fire over the last week, marking the anniversary of the conflict in which 158 Palestinians were killed, according to the Palestinian Centre for Human Rights. Six Israelis also died in the conflict.