SAN DIEGO -- A fight involving three people in front of a downtown grocery store Friday left two men with stab wounds and one of the combatants under arrest, authorities reported.

The brawl in the 900 block of Park Boulevard erupted for unknown reasons shortly after 1 p.m., according to San Diego police.

Officers arrived to find one man lying on the sidewalk in front of Popular Market, bleeding profusely from a large gash to his abdomen, and another standing nearby, covered in blood, SDPD spokesman Jim Johnson said.

Police arrested the man who was still on his feet, then took him and the more seriously wounded man to a hospital, Johnson said.

The dispute also involved a woman who apparently has been romantically involved with both men, SDPD Capt. Chris Ball said. During the fracas, one of the men punched the woman, according to witnesses.

The weapon used in the fight was believed to have been a box cutter, the captain told reporters.