U.S. Marines today captured former Grenadan Deputy Prime Minister Bernard Coard, the rival of Prime Minister Maurice Bishop whose attempt to take power two weeks ago led to last week's military coup and killing of Bishop and three of his loyal ministers.

Coard, 39, was captured in a house on the outskirts of this picturesque, hilly capital where he had been hiding with his wife, Phyllis, and two leading Marxist figures in the coup--Minister of National Mobilization Selwyn Strachan and Lt. Col. Lionel James, who became the deputy chairman of the Revolutionary Military Council that replaced Bishop's government after his execution Oct. 19.

According to marine gunnery Sgt. Mike Stelzel, the leader of the Marine squad that captured Coard, the former deputy prime minister gave himself up only after the marines surrounded his hideout and ordered everyone out.

"Coard was the last person to come out of the house," Stelzel told journalists, "the one thing I remember he kept saying was, 'I'm not responsible, I'm not responsible.' "

Coard was captured as the 5,000-man U.S. force on this tiny Caribbean island continued to meet scattered resistance around the countryside from snipers, and extensive U.S. air action continued along with ground "search and destroy" patrols. But the U.S. military commander said that "for all intents and purposes, the fighting is over here."

Adm. Joseph Metcalf III said that the casualty tally among "enemy combatants" had risen to 69 dead and 56 wounded.

Metcalf said that he was unable to break down the number of dead, which rose from 36 Friday, between Cubans and Grenadans. He also said that the number of enemy casualties was bound to climb once a systematic survey was conducted of all who had died in the past five days' sporadic fighting.

"I know the figure will be higher when we get a final count," Metcalf said to journalists in the partially completed airline terminal building at Point Salines. "Why, just this morning we found a field near here full of bodies.

"These people have been in that field a long time, and no one feels particularly good about counting them," he said, noting that the bodies were "rather warm," apparently referring to their decomposition in the sun.

Friday, Metcalf said his intelligence estimate indicated that, with 638 Cubans captured, there might be at least 450 still loose. But in Washington today, Pentagon officials revised their original estimate of 1,100 Cubans in Grenada at the time of the invasion, to between 700 and 750. This is about the figure Havana has cited since the invasion began, one that would put the number of Cubans still possibly resisting down to a few dozen.

For the first time, Metcalf indicated that those resisting his forces were not just Cubans but also members of Grenada's People's Revolutionary Army, estimated before the invasion to number 1,200. Many were believed to have infiltrated back into the civilian population.

Journalists brought here today for a limited guided tour by the U.S. military were fired on only a mile east of the Cuban-built airstrip at Point Salines that serves as the main U.S. forces staging area on the island. No one was injured, and despite patrols on the ground and by Cobra helicopter gunships, no sniper was found.

To counter this continued, if scattered, resistance, U.S. C130 Spectre gunships were in action in the air east of the airport for the fifth straight day. They circled continuously over the densely vegetated hills beyond the U.S. forces' perimeter and fired at the ground with their rapid-fire 20mm "mini-gun" cannons.

At the same time, four carrier-based A7 Corsair fighter bombers swooped in and around the same hills for more than an hour in support of Ranger "search and destroy" squads.

Meanwhile, marines in St. George's continued to round up Grenadans suspected of being supporters of the now ousted military government.

The capture of Coard and his colleagues was the most important political catch since the U.S. forces landed on the island. They were followed by a token force of 300 policemen and soldiers from six Caribbean nations.

According to Capt. David Karcher, the commander of the Marine force that captured Coard, he dispatched Stelzel with a reinforced squad to search for Coard after an unnamed Grenadan civilian approached him and said that an "important man" from the military government was hiding in a nearby house and was planning to move to a more secure hideout within an hour.

Stelzel's squad first came upon a Grenadan Army barracks whose two remaining defenders fled, leaving behind a Soviet-made armed personnel carrier that the marines tipped over an embankment to disable it. The marines then surrounded Coard's hideout. After ordering all inside to come out and getting no reply, Karcher said, "I then told them they had two more chances to give themselves up before we started shooting. After the second warning--and after I had conspicuously moved an antitank gun to point at the house--there was another pause of five minutes.

"Just as I was about to give the order to storm the house, the door opened and the occupants, six people in all, came out one by one," Karcher said.

Inside the house, the captain said, the marines found three loaded revolvers and two Soviet-made AK47 assault rifles.

Coard and his party were taken by truck down to the Queen's Park cricket grounds that the Marines have turned into a helicopter landing zone. After an hour, he and his party were helicoptered to Point Salines, where an unspecified number of Grenadan and Cuban prisoners is being held by units of the 82nd Airborne division.

Coard had not been seen or heard from since the events leading to the invasion began Oct. 14, when Strachan announced that the ruling leftist party had decided to limit Bishop's power and to increase Coard's. Less than a week later, on Oct. 19., Bishop's supporters massed to release him from house arrest, leading to a confrontation with soldiers that resulted in the death of Bishop and some of his supporters.

Gen. Hudson Austin then announced that he had taken over the country at the head of a Revolutionary Military Council, whose membership did not include Coard.

Austin's whereabouts continued to be unknown, although Metcalf gave credence to previous rumors--unsupported by any hard evidence to date--that Austin was holed up somewhere with two hostages.

"To the best of our knowledge, Austin is holding hostages, though our information is they are not Americans," the admiral told journalists. "That is what I believe, and that is the assumption we are operating on."

He declined to say where he thought the hostages were being held. He also declined to say what he planned to do with Coard and his associates.

"What are we going to do with them?" the admiral asked gleefully. "I'm not going to tell you what we are going to do with him. We certainly aren't going to give him a good-conduct medal."

In the streets of St. George's, meanwhile, Grenadans continued to stay near their homes, chatting about the U.S. presence that most seemed to approve of, speculating about what sort of government they might get and watching U.S. marines search for new suspects.

In one such incident witnessed by journalists, Capt. Karcher and his men surrounded a red Japanese sedan just after it moved through a roadblock and forced its two male occupants out of the car.

The two men were then forced into a spread-eagle position against a roadbank while some marines leveled their M16s at their backs and others searched the vehicle for incriminating documents.

"We were told by a Grenadan that these men are revolutionaries in the People's Revolutionary Army," Karcher said. "We have reason to believe that one is a . . . company commander and the other is a captain in . . . intelligence."

After documents were allegedly were found to back up this suspicion, the two men had their hands tied behind their backs with electric wire and were marched off down the road.

Louis Padmore, a customs broker who watched the scene with his wife from their driveway, showed guarded approval at the rather dramatic arrests.

"Bishop was really not a bad man," he said. "In fact he was really keeping them Coard's men back from what they planned. He was the fly in the ointment. After they killed him, they seemed ready to get everything they wanted."

Padmore and a neighbor, Theopholus George, said that the problem was they could think of no one who actually might head a government.

It was a common dilemma expressed by many St. George's residents. As David Filbert, 34, a mason, said, "I don't know that we have any key people left to govern Grenada. I really don't know where we go from here."