GAZA, Jan 5 (Nidal al-Mughrabi/Reuters) - An Israeli air strike killed a commander of a Palestinian militant group and wounded four other militants in the Gaza Strip on Tuesday, the group said.

An Israeli military spokeswoman said Israel had launched the strike against gunmen planning to fire rockets at southern Israel and a security source said a militant had been killed.

The raid came a day after the Popular Resistance Committees, a militant group based in Hamas-ruled Gaza, said its members had fired a mortar at Israel in response to a military raid.

In a statement, the militant group accused Israel of carrying out a targeted killing by aiming aerial fire at its armed members while they were in the town of Khan Younis after dark.

It said the attack had killed local commander Jihad Smairi, the first fatality of the Israeli-Palestinian conflict this year.

Israel killed six militants in two separate confrontations with militants in Gaza and the occupied West Bank late in December.

Lethal violence had grown less frequent since a war in Gaza a year ago Israel said it launched to stop militant rocket fire at Israeli towns, in which 1,400 Palestinians and 13 Israelis were killed.

Most of Israel's recent air attacks in Gaza have targeted tunnels it says militants use to smuggle in weapons from Egypt, and often these strikes have not caused any casualties.

Any increase in violence could complicate U.S.-backed efforts to renew Israeli-Palestinian peace talks stalled since late 2008, and German-mediated talks for a possible swap to free an Israeli soldier held in Gaza since 2006 in exchange for hundreds of Palestinians in Israeli jails.

(Reporting by Nidal al-Mughrabi; Writing by Allyn Fisher-Ilan; Editing by Michael Roddy)