Israeli air strikes target factory, tunnel in Gaza

* No injuries reported in air strikes

* Cooking gas canister explosion kills six in tunnel

(Updates with six killed in tunnel incident)

GAZA, May 29 (Reuters) - The Israeli military carried out air strikes against targets in the Gaza Strip on Saturday, an army spokesman and Palestinian witnesses said.

No one was wounded in the attacks, Palestinian medical workers said.

The army spokesman said the air strikes targeted a metal factory in northern Gaza that Israel believed was used to make weapons and a tunnel dug by militants near the Israeli border.

He said the strikes were in response to a rocket fired from the Gaza Strip towards Israel on Thursday.

In a separate incident, six Palestinians were killed and several injured when a cooking gas canister smuggled from Egypt exploded in a tunnel, medical workers said.

Palestinians use tunnels under the Egypt-Gaza border to smuggle in everything from staples to weapons to skirt an Israeli blockade on the enclave. Israel tightened its blockade in 2007 after the Islamist group Hamas took control of Gaza.

Israel launched a devastating military offensive in Gaza in December 2008 with the declared aim of stopping daily rocket fire aimed at its southern cities. (Reporting by Nidal al-Mughrabi; Writing by Joseph Nasr, editing by Tim Pearce)