Palestinian gunmen shot and seriously wounded a police officer Friday who came to settle a dispute in the West Bank town of Tulkarm, witnesses and hospital officials said. The gunmen fired on police who were called to deal with an argument in a coffee shop, witnesses said. The gunmen attacked and fired at the police officers when they entered the cafe, the witnesses said. One police officer was in critical condition after being shot in the stomach, hospital officials said. The Al Aqsa Martyrs' Brigades, a militant group with links to Palestinian leader Mahmoud Abbas' ruling Fatah party, which has often been involved in internal fighting, said it was not responsible for the gun battle. No other militant group has claimed responsibility. Palestinian police officials declined to comment on the incident. Palestinian towns and cities in the West Bank and Gaza have been plagued by internal fighting, with armed gangs and militant groups filling the vacuum left by an ineffective police force. Abbas has said he wants to restore law and order to his chaos-ridden cities and empower his police, but has so far been reluctant to confront and disarm the militant groups. The US and Israel have repeatedly demanded the militants be disarmed.