Police said today that a bomb appeared to have caused yesterday's explosion in an Iranian-owned shop in West London, and an associate of a man killed in the blast accused the Iranian Embassy here of responsibility.

The dead man was identified as Bijan Saezali, 22, believed to be the son of the owner of the shop, a newsstand that specializes in video tapes and literature opposed to the Islamic rule of Iranian leader Ayatollah Ruhollah Khomeini. Twelve persons also were injured in the blast, two of them seriously.

The embassy denied any connection with the incident. It charged that the explosion was part of an anti-Khomeini campaign by "counterrevolutionary Iranians," and tied it to two recent bombings in Tehran that killed 30 people.

An embassy statement implied that the bomb had been intended for the nearby Iranian consulate, but had "misfired," with Saezali suffering "the bloody consequences of his own terror."

The explosion yesterday afternoon initially was attributed to a gas leak, but no leak was found today when gas lines leading to the shop were examined. Police said that rubble from the shop still was being examined for conclusive evidence, but that they now believe a bomb was the cause.

If confirmed, the bombing would be the first lethal clash between pro- and anti-Khomeini Iranians in London since 1980, when six Iranian gunmen took over Iran's embassy and held 19 hostages there for six days. Iran charged that the gunmen were backed by Iraq, its enemy in a war now almost six years old. Five of the gunmen were killed when British troops stormed the building.

After the 1980 siege, Iran moved its consulate to Kensington Court in west London, a small road immediately behind the Kensington High Street location of the destroyed shop.

The statement issued by the embassy today said, "We have received information that an unidentified group was intending to carry out a terrorist act on the Iranian consulate. According to our report, the one who wanted to put the bomb in the consulate was himself a victim of his own terror. Reports suggest that the attack misfired, with the perpetrators suffering the bloody consequences."

Iran "strongly condemns all acts of terrorism," the statement said. "Iran itself has been a victim of such terrorism, and thousands of innocent lives have been lost in the last seven years" since Khomeini replaced the Iranian monarchy of Shah Mohammad Reza Pahlavi.

London is a center for anti-Khomeini Iranian dissidents, second only to Paris, where exile organizations are headquartered. The shop where the explosion took place was said today by sources close to the exile community here to be owned by an Iranian monarchist who was a former film star.

In addition to anti-Khomeini literature, the shop was a distribution point for crude video tapes containing denunciations of the Iranian clergy and short plays ridiculing them. One example shown on British television today depicted a group of Islamic clergymen drinking while a belly dancer performed.

A man who claimed to be a friend of the man killed in the explosion said this morning that the victim had told him last Saturday that he had been subject to "threats and abuse and trouble-making by the Iranian Embassy staff."

The man, who was identfied only as "Mohammed" during a British television interview this morning, said, "my friend had managed to make a beautiful video of the late shah's funeral, and smuggled it into Iran. The embassy staff and circles close to the embassy inquired why this anti-Khomeini video should be made.