ABASSAN, Gaza Strip — Militants from the Hamas and Fatah movements clashed with assault rifles and shoulder-held missiles Monday, killing three people in the latest sign the rivals could be heading toward a large-scale confrontation. The groups fought again today in downtown Gaza City, wounding nine people, including five children.

Prime Minister Ismail Haniyeh of Hamas called for restraint and ordered his security chief to impose order. But tensions remained high as the sides accused each other of instigating the violence.

Friction has been rising since the Islamic militant group Hamas ended Fatah's four-decade control of Palestinian politics with a victory in January parliament elections.

Haniyeh and moderate Palestinian President Mahmoud Abbas of Fatah have been wrangling over power, particularly over control of security forces. The friction has been compounded by a growing financial crisis, the result of Western economic sanctions against the Hamas-led government.

Monday's violence began before dawn in the farming community of Abassan in southeastern Gaza. Hamas tried to kidnap a Fatah member, apparently to settle an old score, said Fatah spokesman Tawfiq Abu Khoussa.

The kidnapping ignited several hours of violence that included more kidnappings and fire fights. One Hamas militant was killed. All captives were released after negotiations.

Hamas gunmen ambushed Fatah militants driving on the main road in two jeeps with red government license plates. One jeep was hit by a shoulder-held missile, killing two Fatah gunmen.