LONDON, June 22 (Reuters) - Copper prices in London hit a seven-week high on Thursday after a sharp drop in available stocks in warehouses registered with the London Metal Exchange (LME) to their lowest since 2021.

Benchmark copper on the LME was up 0.8% at $8,675 a metric ton by 1017 GMT after touching its highest since May 2 at $8,711.50 and breaking above the 100-day moving average of $8,696.

"Things are looking quite tight for copper at the moment," said Dan Smith, head of research at Amalgamated Metal Trading.

LME inventory for the metal used in power and construction has been low for a while and the big jump in cancelled warrants has further reduced the amount of available material.

Technical indicators give $8,870 as a price target over the next couple of weeks, Smith said, adding that stocks show that there are people keen to hang on to copper.

In top metals consumer China, copper inventories in warehouses monitored by the Shanghai Futures Exchange fell 1.1% this week.

Chinese markets are closed on Thursday and Friday for the Dragon Boat Festival, but sentiment there has been weighed down by a lack of meaningful economic stimulus that could support growth in demand for metals.

Supporting base metals prices on Thursday was a weaker dollar, which makes dollar-denominated commodities more attractive to buyers holding other currencies.

Among other metals, LME lead and tin hit their highest since January 30 and April 19 respectively. By 1017 GMT lead was up 0.4% at $2,181.5 and tin had added 0.8% to $27,525.

Aluminium rose 0.7% to $2,238 as it continues fighting with resistance coming from the 21-day moving average of $2,240. Zinc gained 1.7% to $2,456.5 and nickel was up 0.6% at $21,365. (Reporting by Polina Devitt in London Additional reporting by Mai Nguyen in Hanoi Editing by David Goodman)